Phys4AS17 AAChung

Lab 13: Magnetic Potential Energy Amy, Chris, and John April 17, 2017 Today's lab is to verify that the conservation of energy applies to a system where a cart with a magnet on a friction less track hits a magnet of same polarity.  Theory:  When a cart is at the position closest to a fixed magnet, the carts' Kinetic Energy is momentarily zero, where the energy in the system is stored in the magnetic field of as magnetic potential energy, then rebounds back. Where the potential turns back to Kinetic Energy.  Apparatus and Procedure:  For this lab we use a glider on an air track as our cart on a friction less surface.We needed a glider cart, an air track, books to raise one end of the track, a phone, a caliper, and logger pro. First we had to level the air track in order to measure the angle as we raise the track more accurately.    We raise one end of the track where the cart will end up at some equilibrium position, where the magnet...

Lab 11: Work-Kinetic Energy Theorem Amy, Alex, and Cristian April 10, 2017 Today's lab was to prove the work energy theorem by comparing the change on Kinetic energy and using the formula for work which is the force times distance. Theory:  By comparing the two formulas for work we can calculate the Kinetic Energy in the system of a cart with a hanging mass. In theory both results should equal each other. We are also measuring the work done on a cart by a constant force as well as a non constant one. Apparatus and Procedure:   For this lab we had to measure the work done on a cart using a motion sensor, a force probe, a track, and a laptop. The motion sensor had to be constantly calibrated in order to get accurate data.  The first experiment had a level track with a friction-less cart riding on the track. On the cart was a 500 gram mass and a force sensor that had a string tied to it that ran over a pulley on the edge of the track tied to a hanging m...

Lab 10: Work and Power Amy, Chris, and John  April 03, 2017  Today's lab is about calculate the power output we have by performing physical activities. Theory:  Work is defined as a force done on a object during a displacement period.  Where F dot delta x is defined using the dot product. But a quantity that just work does not account for is time. You could supply the same amount of force to move an object the same amount of distance but there is no indicator for how fast this task was carried out. This is where the concept of power comes in, the time rate at which a work in done :  Power=Work/Time Apparatus and Procedure:  For the first part of the experiment we had to lift a backpack up the side of the building. The backpack had pre-measured weights and we had to time how long it took us to lift it up a height h. As for the second part, we had to time ourselves walking up the stairs and then run the same staircase and time it as well. ...

Lab 9: Centripetal Acceleration with Motor Amy, Chris, and John April 03, 2017 Today's lab was about establishing the relationship between the angle a string forms with a tripod and the angular velocity an object has.  Theory:  We were given that there exists a relationship between angular speed and centripetal force.  We know that the centripetal force of the object we are spinning on this lab is:  F=ma(centripetal acceleration) which also equals mrw^2 (where w is angular speed). As shown, if the centripetal force increases, the x component of the tension also increases which changes the angle theta that the string makes with the vertical. If we call height from the ground to the top of string, H, and the height from ground to the mass, h. We can find the vertical length of the string at a particular angular speed, expressed as H-h. This forms a right triangle which lets us solve for the angle theta (L is the length of the string): Because of ...

Lab 8: Centripetal Acceleration vs. Angular Frequency Amy, Chris, and John March 29, 2017 Today's lab was about finding the relationship between centripetal force and angular speed, with multiple varying scenarios. Then graph our findings and find a graph with the best linear fit that shows us the best correlation.  Theory:   We know for an object moving in uniform circular motion, the direction of acceleration is towards the center. The force that corresponds with this acceleration is called the centripetal force and in  equation, centripetal force  is  the ma. It can be interpreted as the net force. If we had different forces that contribute to the circular motion, the sum of those forces would be equal to your centripetal force. In our lab, looking at the setup from the side of the disk, the free body diagram of the mass looks something like:     We derived the equations in order to change our variables one at the time and figu...

Lab 7: Modeling Friction Forces Amy, Chris, and John  March 22, 2017 Today's lab was to model friction forces in five different experiment, in both flat surface and sloped surface scenarios. Compare results obtained in experimentation with derived values for kinetic and static friction. Theory/Introduction : Static and Kinetic Frictional Forces (1) Static Friction (on a flat surface): Frictional forces have two different characteristics, one for non-moving cases (static) and move (and possibly accelerating) cases (kinetic). The magnitude of static friction scales along with the applied force that opposes it until it reaches the maximum static friction point where your object starts to move and convert over to a constant kinetic frictional force (shown in picture above). Static frictional force can be modeled mathematically by: The less than or equal sign is used since the force of static friction scales along with the force applied. If the force applied is 0,...