Rubber Band Cart Launcher

Big Question:

How are energy and velocity related?

 ~ This week we launched a red air glider using a rubber band. With the "Photogate" sensor, we were able to measure the velocity when it went through the gate. We varied the distances at which the rubber band was pulled: .01 m, .02 m, .03 m, .04 m, and .05 m.

 ~ From this data, we can see that as the velocity goes up, the energy goes up also. Then we graphed our data with the Energy (J) on the y-axis and velocity squared on the x-axis.

 ~ With this graph, we were able to derive an equation relating mass, velocity, and energy with the equation of a line: y=mx+b. After finding our slope (.2), we saw that it was half the mass of our red cart (.4). Then we substituted "E" (energy) for y, 1/2 m for m, and velocity squared for x, E=1/2mv^2. 

Speed of a Slingshot

 ~ In this picture, the distance at which this person pull back the sling, the faster the rock will go towards the apple. Right now, there is potential energy in the sling and it will be transferred to the rock when the person lets go of the sling.