Here is a useful worksheet we have used with PE and KE. It calculates the PE and KE of a run away hot dog cart that runs into a spring. On the first worksheet, I have included the equations on the worksheets. I have included a second worksheet exactly like the first without the equations showing.
A local hot dog vendor forget to set his emergency break while he goes in the back of the truck to take a nap. It’s velocity is essentially zero when a passing car rattles the truck and sends it plunging downward. Luckily, for the hot dog vendor there is a spring loaded guard rail at the bottom of the hill that brings the dogs to a safe stop. The truck and its driver have a mass of XXXXX and sits on a XX high hill.
A. Using 10 m/sec2 for g, what is the weight of the car in Newtons?
B. What was the amount of potential energy stored in the truck at point A?
C. What is the velocity of the cart at the bottom of the hill at point B?
D. If the guard spring has a rating of xxxxhow much will the guard rail crunch absorbing the kinetic energy of the truck.
E. If the original length of the guard rail was xx, what is its crunched length?
F. Is the collision with the guard rail elastic or inelastic and why?
G. If these canisters represent the energy at each point fill them in as appropriate. Does the sum of the potential and kinetic energies remain constant throughout the journey?