The Top 10 Laws of Physics

1.)    Newton’s First Law -

“Every object continues in a state of rest or of uniform speed in a straight line unless acted on by a nonzero net force.”

Another way to say this is that an object at motion with stay in motion and an object at rest will stay at rest unless acted on by an outside force. The prime example of this law is where someone has set up a dinner ware set and pulls the table cloth out from underneath it. The dishes stay in their restful state because their inertia is greater than the force acted on it.

This same concept applies to objects in motion. An object at motion with continue to move without turning or gaining speed.  This was the concept demonstrated by our hovercraft lab in the beginning of the year.  Although, this concept is mainly evident in space, we were able to recreate a friction-less environment by keeping the craft floating above the ground.

2.)    Newton’s Second Law –

We learned all about Newton's Second Law and its behavior towards objects that may have an unbalanced force on them in the air. Newton's second law states that the acceleration of an object is dependent upon two variables - the net force acting upon the object and the mass of the object. The acceleration of an object depends directly upon the net force acting upon the object, and inversely upon the mass of the object. So as force acting on an increase, the acceleration of that object increases. As the mass of the object increases, the acceleration of that object decreases.

In other words acceleration is directly proportionate to force and inversely proportionate to mass. The equation below uses Fnet which can also be determined by mass times acceleration.

A = Fnet/m

3.)    Newton’s Third Law of Motion

Newton's third law of motion states that, "for every action there is an equal but opposite reaction." In the beginning of this lesson, we start to understand the concept of forces and interactions. We grasp a concept of forces such as pushing or pulling, but realize that no force or interaction occurs alone. Every force is part of an interaction between one thing and another. For example when a boxer uses his force to punch a large punching bag, the first force on the bag is from the boxer's fist, which causes the bag to dent. However, the punching bag also applies a force back on the boxer's fist. If the boxer was to punch a lighter tissue that was in midair, then the tissue could only exert how much force was exerted on it. This is why an interaction requires a pair of forces action on two separate objects.

After understanding this concept, we then moved to learn about Newton's Third Law of Motion and how it cooperated with action and reaction pairs. Newton's Third Law is summarized by stating, "whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first." But how do we grasp this concept using demonstrations. For example, when you walk, you interact with the floor. You push against the floor and the floor pushes against you. These pairs of forces are the same. So when stating "YOU PUSH on FLOOR" (This being the action) "FLOOR PUSHES on YOU" (This being the reaction) Next, this concept goes further in depth, which helps you understand how actions and reactions work when two object differentiate in mass. The book states, "As strange as it may seem, a falling object pulls upward on Earth  with as much force as Earth pulls downward on the object. The resulting acceleration of the falling object is evident, while the upward accelration of the Earth is too small to detect." When am apple is falling out of a tree the apple is pulling the Earth upward as much as the Earth is pulling the apple downward. Therefore "EARTH PUSHES APPLE DOWN" = "APPLE PUSHES EARTH UP." And to an extent we learn about how force is related to mass and acceleration proportionately with the demonstration of a cannon and a cannonball. When using the formula (F/m) = a, we know that if you have a smaller force then you are going to have a greater acceleration, and if you have a smaller acceleration you are going to have a greater force. We see this when demonstration a cannon firing. The force exerted against the recoiling cannon is just as great as the force that drives the cannonball inside the barrel. During the class we also played a game of tug of war that helped us understand the concept of forces applied. The guys competed against the girls in the game of tug of war, with one exception the guys were wearing socks on the hardwood floor. Anyways, the girls one because they were able to put more force on the ground which allowed them to pull harder.

4.)    Rotational Inertia–

The definition of tangential speed is the direction of the motion tangent to the circumference of the circle. We learned that tangential and linear speed can be used interchangeably. Rotational speed, however, involves the number of rotations or revolutions per unit of time. We used these two definitions with many everyday problems and scenarios that correlate appropriately. The real life exercise we used was the merry go round question. All of the fine physics students in Ms. Lawrence's class embarked on a journey to the outside world, were we lined up and locked arms. We learned now that even though the inside center point of the rotating line, trying to represent the merry go round, the students who were on the outside of the line were moving at a faster speed in order to cover the same ground as the students on the inside. This is due to the fact that they have the same rotational speed because they are connected, but have different tangential speeds because the outside needs to cover more distance than the inside.

5.)    Law of Gravity and Free Fall –

This animation demonstrates that when an two objects are in free fall they hit the ground at the same time disregarding the mass difference of each object. It also demonstrates that when two objects are dropped and are encountered with air resistance they most likely will not hit the ground at the same time. This for many reasons. One reason being that each object may have a different surface area that causes more or less air resistance. Another reason is that they will have different mass and have a stronger force of gravity pulling them towards the Earth.

6.)    Law of Conservation of Momentum

Momentum is simply inertia in motion. Or can also be defined as Momentum = (Mass x Velocity) We learned that a moving object can have a large momentum if either its mass or velocity are large or if both its mass and its velocity are large. One example we used in class was comparing a truck and a small car and seeing how their mass and speed compared to their momentum proportionately. Next, we learned about momentum. We learned that if the momentum of an object changes. then either the mass or the velocity or both changes. This is shown by the quantity force times time interval, or, Impulse = Ft. The greater the impulse exerted on something, the  greater will be the change in momentum. So therefor, Impulse = change in momentum. One example that really helped me grasp this concept was the example that showed that if a boxer "rolled with the punches then the impulse would be less."  This was shown as (little F)(BIG t)= (Big F)(little t) This is where the force over a greater time period would be less as opposed to the force being greater over a shorter time period. Then, we moved into the concept of objects bouncing. We learned that when an object hits something it has an initial impact and if it is not absorbed, has another impact that makes the object bounce off. This creates two forces on the object if the force is not absorbed. The demonstration where Mrs. Lawrence was in the rolling chair and threw and caught a heavy object and she continued to move backwards really helped me understand this more in depth. The final thing we looked at in this unit was the conservation of momentum.

From Newton's second law, we learned that to accelerate an object, a net force must be applied to it. This was generally the same in this chapter except written and explained differently. If we wished to change the momentum we would have to change the impulse. The demonstration the Mrs. Lawrence used where two cue balls were hit together and one stopped and the other kept moving helped me understand in real life terms of how momentum is transferred.

7.)    Law of Conservation of Mass

This Law states that matter cannot be created nor destroyed only transformed. The mass is transformed when the transformation is preformed and the matter stays the same.

8.)    Law of Conservation of Electric Charge

When dealing with electric current it is important to understand how conductors and insulators work.  A conductor is a when any material that make the electrons “loose” and transfer energy between it. A good conductor for example, is any type of metal. Electrical wires in circuits consist of metal to allow the electrons to flow through the wire and bring energy to the source. On the outside of the wire is a coating that is an insulator. An insulator is an item that does not allow electrons to pass through it.

9.)    Coulomb’s Law

Coulomb’s Law deals with an electric charge over a distance.

“Coulomb's law states that the electrical force between two charged objects is directly proportional to the product of the quantity of charge on the objects and inversely proportional to the square of the separation distance between the two objects.”

10.) Ohm's Law 

Ohm's law states that “the current through a conductor between two points is directly proportional to the potential difference across the two points.”

V=I/R

Wind Turbine Blog

1. ) There were many major physics concepts covered in this project that we were introduced to in previous units. In this case, making a wind turbine to generate electricity contains many topics from our past units of magnetism and electricity. The idea of building a wind turbine contains many  materials and strategies in order for it to work. The wind turbine contains different sets of physics components that allow it to function. One set of this happens to be electric component. The way the turbine is able to produce electricity is a chain reaction from the other components. When the wind blows on the fan blades of turbine it spins the electric generating motor. This motor is made from the electric current of a battery running through the magnet and spinning the coils. When the armature spins it generates a current which positive and negative wires are connected allowing electricity to be produced.

2.) To reproduce the project that we completed you  would need a certain set of materials to make sure the turbine worked properly. First of a we started out buy buying a structure for the wind turbine to make it stable and hold the working parts in place. We used PVC pipe because not only is it sturdy it also is hallow and can contain running wires. In addition to this, we purchased a shaft to spin when the wind blew the fans and work as an axle. We created an electric motor, as mentioned above, out of a battery and a magnet connected to an armature that allows it to produce electricity. The armature was created out of copper coils bound together to work as a good conductor for the current running through it. Lastly, we attached wire to both the positive and negatives ends of the armature it produce a current and generate electricity. 

                                     

3.) From this project I learned many factors in order to produce more electricity and understand this physics concept more clearly. I learned that in order for more electricity to be produced it directly corresponds to the number of turns in the armature to produce that electricity. For example, when there is faster wind, the armature would spin faster and induce more electricity. Also from a construction standpoint the wind blades should not be flimsy and be able to spin easily in the wind with less friction by making them larger. 

Motor Blog

        The motor works because each part of the motor has specific function that causes spin. First, and electric current in a magnetic field will experience a force. In the current carrying wire the two sides are in a circular shape, each side is scraped and allows it to experience both positive and negative force of the magnetic field causing it to repel and spin. This is why each end is scraped differently. The two forces creates a torque to torque to rotate the coil. The coil contains several loops on an armature to provide a more uniform torque produced by the electric magnet. This motor could be used to preform simple tasks as in rotating a wheel or spinning a fan.

Electricity Unit Blog

            This unit began with a brief overview on the basics of electricity. Electricity is the name given to a wide range of electrical phenomena that, in one form or another, underlie just about everything around us. We learned about the many different forms of how electric charges can be transferred. We jumped into learning about the basics of electric charges and how the terms of positive and negative correspond directly. Before learning this we had to understand the matter of protons and elections in items. Although this physics class didn’t get into too much about the matter of an atom we had to understand the behavior of each.

When dealing with electric current it is important to understand how conductors and insulators work.  A conductor is a when any material that make the electrons “loose” and transfer energy between it. A good conductor for example, is any type of metal. Electrical wires in circuits consist of metal to allow the electrons to flow through the wire and bring energy to the source. On the outside of the wire is a coating that is an insulator. An insulator is an item that does not allow electrons to pass through it.

Next, we learned about charging and the different types of charging that allows energy to be transferred. The first type of charging we learned about was charging by friction and contact. Electrons can be transferred from one material to another by simply touching. In class, Mr. Rue demonstrated this with creating the scenario of the thought of laundry in a dryer and how clothes tend to stick together afterwards.  This is because there are certain types of fabrics that steal electrons from one another. He demonstrated this by taking two different socks made with two different types of materials and rubbing them together. This allowed one sock to steal electrons from another and leave the one that had its electrons taken from it positively charged. The other type of charging that we learned about was charging by induction. Charging by induction is when an already positively or negatively charged item is brought so close that the attracting opposite forces generate so much energy that a spark is created.

      

The next thing that we learned about that relates directly to the topic of charging is charge polarization. Charge polarization is when either side of an object is oppositely charged.  This is when both the positive and negative atoms of a molecule become aligned to generate a type of homeostasis for the object. 

 

Then we moved on to the next chapter to learn about Electric current. Electric current is simply the flow of electric charge. There are many variables that correspond to directly it. Voltage is the an electromotive force or potential difference expressed in volts. Potential difference can be defined as the charge that flows from one end to another with different electric potentials. Current is defined as the direction of the flow of positive charges. In metals, which make up the wires and other conductors in most electrical circuits, the positive charges are immobile, and the charge carriers are electrons. Resistance is an electrical quantity that measures how the device or material reduces the electric current flow through it. The resistance is measured in units of ohms (Ω). These factors play an important role in the ability particles have to flow through a circuit. 

When learning about the different types of circuits we had to understand these factors and comprehend that for a circuit to work there has to be a continuous flow of electrons to make the circuit complete. There are two different types of circuits that we learned about. Series circuit was the first and this is here each lamp, for example is connected end to end receiving the same amount of current. The next type of circuit we learned about was a parallel circuit. Where the same voltage is applicable to all circuit components connected in parallel. We also learned that a fuse is a box that is used to regulate the amount of current that runs through a circuit. If there is too much current, then the fuse will bust and the circuit will overload. 

This unit was very new to me. I learned alot more in the unit about a lot broader range on concepts than I had in other units. I believe that I did better in retaining the information of this unit and preparing myself for the tests and quizzes. 

Current Resource

In this odd and highly political cartoon the different people explain the different types of electric current and how it can be determined. Current is the flow of particles and in order to figure out what type of current it is you need to know whether it is positive or negative flow of particles.

Voltage Resource

This old yet outstanding video helps explain what potential difference is and how it relates with examples and diagrams. It explains how energy is relevant to the kinetic and potential concepts that we have previously studied.

Physics of the Mousetrap Car

1. 2.87 seconds (1st in class) 
2. 
             -In the picture above, the car that carter is holding is, in fact, the mousetrap car that won first place in our class. There are many different parts of the car that make this car move as it should. 
            
             -Aluminum Frame - used for the stability of car to not fall apart when moving.
             -Mousetrap - The mousetrap is the "engine" of the car, making the lever arm move to propel the
 car. 
             -Cork- The cork on the back axle of the car is used as our transmission. This part is where the string wraps around to spin the back wheels. 
            -Axles and Wheels - The axles and wheels are what makes the car's movement possible. As the cork spins the axle rotates with it which causes the wheels to spin with it as well. 
            
            -Metal Rod- The metal rod acted as the lever arm for our car. It reacted when the mousetrap sprang and pulled the rope that spun the cork which spun the wheels. 

3. 

4. 
   a.) Newton's First Law of Motion (An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.) 
           
              -In this experiment, Newton's first law played a very important role on the mousetrap car, especially when it came to speed and distance of the actual race. When the mousetrap car was started, it was at rest. Yet, there was a force that acted on it (Mousetrap) and it began to move. In a friction less environment the car would have  kept going on forever. However with friction as the force acting against the wheels it stopped after a while. 

Newton's Second Law of Motion (The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.) 
            - In this experiment, Newton's second law of motion played the important role of of making the force needed to propel the car forward. Knowing the car should be light. It would need less force to be moved by the mousetrap. This relates directly to this law because if the mass is less and the force is the same the acceleration is going to be greater. 

Newton's Third Law of Motion (For every action, there is an equal and opposite reaction.) 

         - In this experiment, Newton's Third Law of motion was responsible for the movement of the car. When testing, we noticed that when the lever arm was released by the mousetrap, it moved the car forward. When the wheels started to spin they pushed the ground and the ground pushed them back, causing equal and opposite actions moving the car in the forward direction. 

   b.) There were two different types of friction that were present when the mousetrap car was moving. The first and obvious type of friction is rolling friction. Rolling friction occurs when an object rolls over another something with wheels or that is circular like a ball. When the mousetrap car was rolling the friction between the floor and the wheels occurred causing it slow down over a gradual time. The other type of friction that occurred was fluid friction. Fluid Friction occurs when a object moves through a fluid, meaning either a liquid or gas. In this case the lever arm was slowed down by the resistance of air to get to one point to the other. Some of the disadvantages we faced by friction was the friction between the wheels and the ground. With this friction present, it slowed down the speed of the car and it was not able to reach its full potential. We tried to solve this problem on a very minimal level by buying wheels that reduced the amount of friction as possible. 

   c.) The factors we took account of when deciding the wheel selection were which ones would make it go the fastest. We decided on small wheels because they would have less rotational velocity and make it easier to spin. We decided to choose wheels that decreased the effect of friction between the wheels and the ground. The back wheels were slightly larger than the front wheels. The reason small wheels are important is because they have to travel less distance to get the same rotation as larger wheels, causing it to move faster. 

   d.) The conservation of energy is defined as "a principle stating that energy cannot be created or destroyed, but can be altered from one form to another."
When doing this experiment we realized that before the car was moving it had potential energy ( the energy possessed by a body by virtue of its position relative to others, stresses within itself, electric charge, and other factors.) because it was at rest. When the care began to speed up its potential energy transformed into kinetic energy (energy that a body possesses by virtue of being in motion.) 

   e.) Carter and I debated endlessly on how long the lever arm of our mouse trap car should have been. We debated on whether the lever arm should be longer or the same length  as the mousetrap car. We finally decided that it should be the same length because it is doing the same amount of work and will make the car move faster if it is the same length compared to it being longer. Overall, for maximum speed, if the lever arm was as long or equal to the mousetrap car then it would pull it fastest. It needed to be something that would move as fast as the mousetrap released would move and not slow it down. This effected both the power and output force of our car. 

f.) Rotational inertia played the role of how easy it would be to spin the wheels. The reason that wheels are used instead of balls is because that it is possible for it to reach inertial velocity faster. The reason that the wheels were small were because of rotational and tangential velocity. The smaller wheels took less time to make a full rotation compared to larger wheels which it means it could cover less distance in more time compared to larger wheels. Although if there were larger wheels on the car the tangential velocity would be different but the rotational velocity would be the same. 

g.) The reason we cannot calculate the amount of work the spring does on the car is because we do not know the force of the mouse trap. As we know, work is equal to force X distance. When the mouse trap is sprung the lever arm travels over a known distance but we do not know what the force is. The reason we cannot calculate the amount of potential energy that was stored in the spring is because we do not know the mass of the mouse trap or the velocity in which it closes. Potential energy equals the change in kinetic energy therefor, if we do not know one we cannot figure out the other. 

Reflection

   a.) From the beginning of the project the original model had a longer lever arm that was needed. After completing multiple trial runs, the thing we needed was more speed. This is what prompted us to change. We decided to make the lever arm as long as the frame of the cart. Allowing the string to pull the transmission at  faster rate, thus, allowing maximum speed. 

   b.) As the trails progressed a few of the problems we encountered were mechanical, meaning there was a flaw in the structure itself. The way we corrected these problems was making sure that the structure was study itself and was meant for the race. 

   c.) To make the car faster, I would decrease the wheel size allowing more rotational speed and less rotational inertia which would increase the velocity of the car. 

Unit 5 Blog Reflection

       As we started Unit 5, the first thing we learned about work and power. We learned that force x time is known as an impulse and work can be defined as the effort on something that will change its energy. We learned about when doing work the force has to be parallel to the force opposing on it. For example, in class we represented this by having students run up and down the stairs of Mitchell timing how long it took them. Each student went in three different intervals of time, walking, running, and carrying a weight. We learned that it takes more force with the same amount of distance to do more work. We also learned how power was directly related. Power is the amount of work done over a time interval. and if the work is great and the time is little then more power is generated.

       The next topic we covered was the relationship between work and kinetic energy. These two concepts fall under the category of mechanical energy. Energy is the "something" that enables an object to do work. Energy is measured. Mechanical energy is the energy due to the position of something or the movement of something. And this is where Potential and Kinetic Energy fall under. Potential energy is the energy stored in an objects readiness. Kinetic energy is the energy of movement.


        The next thing we learned about was the conservation of energy. We learned that it is more important know how energy transforms than understanding what it is. We can represent this transfer of energy by stating the law of conservation of energy:  

           Energy cannot be created or destroyed; it may be transformed from one form into another, but the total amount of energy never changes. 

         We learned how this is directly related to mechanical energy when dealing with potential and kinetic energy. This problem is represented when we see that someone falling. Before they fall that have a greater potential energy and 0 kinetic energy because they are not moving. As they fall slowly, the potential energy is transferred into kinetic energy. and is eventually all transformed into kinetic.

       

        The last concept we covered directly relates to this energy transfer. However, this deals with the transfer of energy for machines. A machine is a device for multiplying force or simply changing the direction of force. This relates directly to the conservation of energy and efficiency. When a machine is in action we know that to figure out its efficiency is equal to the work in/ work out. Although some may think that when a machine does work that some energy is lost because no machine is 100%  efficient. Yet, all this means is that that energy that is "lost" is only transformed into other forms.



       During this Unit we cover some of the main topic that had caught my interest. Before going into Ms. Lawrence's conceptual physics class one of the main concepts that I wanted to cover was the concept of machine efficiency. I really enjoyed this unit and how it gave a brief taste of what there is more to offer in physics.

Machines Resource.

This resource to fit in with the trend of Walker Garrish's sing along blog covers the concept of simple machines and the work put into them. "Work smarter and not harder," the lyrics explain how simple machines are designed to decrease the work put into them to make every day tasks easier.

Work and Power Resource

Work is the effort exerted on something that will change its energy. We can calculate this mathematically by the equation Work= Force x Power. This video explains using examples how energy, work, and power all correlate proportionately. 

Unit 4 Blog

    In Unit 4, the first think that we learned about was about rotational motion and how the circular motion can be defined as either tangential or rotational and how those two correlate. The definition of tangential speed is the direction of the motion tangent to the circumference of the circle. We learned that tangential and and linear speed can be used interchangeably. Rotational speed, however, involves the number of rotations or revolutions per unit of time. We used these two definitions with many everyday problems and scenarios that correlate appropriately. The real life exercise we used was the merry go round question. All of the fine physics students in Ms. Lawrence's class embarked on a journey to the outside world, were we lined up and locked arms. We learned now that even though the inside center point of the rotating line, trying to represent the merry go round, the students who were on the out side of the line were moving at a faster speed in order to cover the same ground as the students on the inside. This is due to the fact that they have the same rotational speed because they are connected, but have different tangential speeds because the outside needs to cover more distance than the inside.


 
   The next thing we learned about was rotational inertia. Rotational Inertia is the property of an object to resist changes in its rotational motion. Like inertia for linear motion, rotational inertial depends on mass and where it is positioned in accordance to the axis of rotation. The real life example we used in this case was the idea of a spinning ice skater. When the Ice skaters arms are out wide spread from her body she begins to slow down because her mass is distributed farther away than her axis of rotation. When the ice skaters arms are inward she is bringing her mass closer to her axis of rotation which allows her rotational velocity to increase varying proportionately.

    The next topic our clever physics students embarked upon was the concept of torque. A torque is the rotational counterpart of force. Torque acts on a force and tends to twist or change the state of motion when force is acting on that object. We learned that torque can mathematically be calculated by Torque= force x leverarm. In this case we learned to calculate the weight of a meter stick by using this equation. The lab that I participated in helped me understand the questions that were on the test. The lab consisted of  balancing the meter stick on a fulcrum (edge of the table) with a 1N force acting on it. and our goal was to calculate the mass without using the scale. We found this finding each lever arms and balancing the torques.



Following the concept of torque we leaned about center of mass and center of gravity. The center of mass can  be looked at by being the point where an object wobbles when off balance. Center of gravity is a term popularly used to describe the center of mass. They share the most common of relevance. The question that was asked in class, was why is it easier to push someone over that is standing straight up rather than in a squatting position. Well, this is because when the feet are in a squatting position then its center of gravity is inside its base of support causing it to have equilibrium.



The last thing we learned about was about centripetal force. Centripetal force is any force that is directed inward on a fixed center of an object. Centripetal is another name for "toward the center" or "center seeking." The example Ms. Lawrence used in class was rotating a plate with strings on it and a cup of water resting on it and twirled it around in a circular motion. In this case, the strings had centripetal force acting on them and the cup of water was pushing out ward.
     

Finding the Mass of a Meter Stick

    In the first step, Zach, Nolan, and I were faced with three different scenarios that helped us try and figure out what we needed to do which, in this case, was find the mass of the meter stick without using the scale and with the the center of gravity only. Our first step was to write out and show the diagram of the problem from the information that was given. Firstly, we knew the the way to find the weight of the ruler was to draw out the diagram and label the side which had the 100g ball on it and using the fulcrum as the edge of the table. We label each side of the diagram with the appropriate force, and distance. 

    The next step was to actually put it to the test. We knew that to find the weight of the ruler we would have balance the torques on each side. Knowing that the equation for torque is torque= force x lever arm. We found both lever arms by finding the center of gravity of either side and subtracting it by the remaining distances. After completing this step we came to the conclusion that the (f=.98) x (24.5) = (f) x (25.5)

    So the next step we needed to preform was to solve for f. To balance the equation both sides needed to be equal to 24.01. and we came to the conclusion that .94 was the force and this was the weight of the meter stick in newtons. The next thing to was do was multiply the force by the force of gravity to get the mass. This, converting it to kg would be equal to 95.9kgm/s^2.  

     In conclusion, the actual mass of the meter stick was 95.8, and because of the fact that my group was on point that day with all aspects of all physics knowledge we were .1 off the actual mass of the meter stick. 

Torque it for me

In this demonstration, the man defines what torque is. He states, that it is a measure of the effectiveness of the force producing rotation. He turns the wrench and shows that the torque in this case is the force that he applied to the wrench and the effectiveness of turning the bolt.

Rotational Inertia With One Handsome Fella

In this video, the handsome gentleman we see here starts off by giving us the definition of Rotational Inertia and what it is associated with. He states, "that inertia is a property that resists in change in motion because of mass, and rotational inertia is the resist in the change in rotational motion that depends on mass." He demonstrates this by balancing a pole on his finger. He takes a weighted clamp and places it on one end of the poll. He flips it from either end to try and figure out which side is easier to balance upon. In this case, it is easier for him to balance the poll when the weighted end is opposite of his finger. This is because the rotational inertia is greater when the weight is opposite. The further the mass is distributed from the rotational axis, then greater the rotational inertia and the greater resistance it has to rotational motion.