6-Apr-2015: Work-Kinetic Energy Theorem Activity

Purpose:
     The purpose of this lab was to demonstrate that work done by an object is equal to the change in its kinetic energy.

Materials:
-Cart and metal track
-Force probe and motion detector
-Spring

Short summary of lab: There were three parts for this lab. The first part consisted of setting up everything to obtain a spring constant. The second part consisted of comparing a calculated kinetic energy with the area of collected data (work). The third part consisted of obtaining the area of a Force vs Position graph which would equal the work done by an object.

Process:
Part 1
     The cart and the force probe should be attached together by the spring. The cart should be at one end of the track with the motion detector on the other end.

     Zero the force probe and motion detector with the spring uncompressed and the cart at rest. Begin to collect data and then move the cart slowly toward the motion detector until the spring is stretched almost 40 cm.
     Your Force vs Position graph should be linear and look similar to this graph.

     The graph of our experiment had a slope of 2.965 which would represent the spring constant K.

     The integral of the graph was 0.2505 which represents the work that was done by the spring.
     We did not verify the distance the cart traveled while data was being collected. However, we know work = (0.5 * K * x^2). Solving for x we get 0.41 m which makes sense.

Part 2
     We measured the mass of the cart and got 0.739 kg. We then added a new calculated column to calculate the kinetic energy of the cart.
     We pulled the cart a distance away from the force probe and towards the motion detector. We collected the data and used the values for when the cart began moving to the point when it collided with the force probe. We then compared the calculated kinetic energy at a point with the area of the graph up to that point. We obtained the following comparisons:

     The first values we compared had were slightly more different than the end values.

Part 3
     For the third part we watched a video of a complicated setup to plot a Force vs Position graph.