Rubber Band Cart Launcher

     In this week's lab, we were asked to determine the relationship between energy and velocity. To do so, we detained the velocity of our red glider cart, using the electronic force probe. We stretched the rubber band to a distance of .01 m, .02 m, .03 m, .04 m, and .05 m. According to the electronic force probe, we documented the velocity of the cart at each distance. We did two trials for each distance and then found the average velocity, the average velocity squared, and we noted the energy measured in joules from our experiment last week. We used our graphical analysis app to determine the graph of our data, using the average velocity squared as the x-axis and the energy as the y-axis. Our graph is shown in the image below:

Using two points on our graph, we found the slope to be 1/2. We converted our y= mx+ b formula into Energy= 1/2 mass x velocity squared.  With K as the elastic constant and Us as the potential energy, we were able to determine that Us = 1/2 k x squared.

We determined that energy in a system always stays the same and that energy and velocity are directly related, and if energy increases velocity must increase. If velocity increases, so will energy.

Real World Connection:

http://ffden-2.phys.uaf.edu/211_fall2002.web.dir/shawna_sastamoinen/Velocity&Kinetic.htm

A rollar coaster can demonstrate the relationship between velocity and energy because if the mass is constant, and the velocity is increased, the kinetic energy must also increase. The article linked above clearly demonstrates this principle as well.