1. The problem statement, all variables and given/known data This is actually a lab- A ball projectile is fired from a spring gun into a free-hanging pendulum, the pendulum catches the ball and travels a certain vertical measurement. #1-Is this an elastic equation #2-Calculate the kinetic energy the instant before and the instant after the collision. 2. Relevant equations K=1/2m*v^2 m=0.0669kg v=6.535 m/s 3. The attempt at a solution #1- I think that this is an elastic equation because no energy is lost in the collision- it is transferred from the spring gun to the pendulum (discounting air resistance). #2- I calculated the kinetic energy using the above equation to be 1.43 J- I am thinking that this is the kinetic energy before the collision and it is -1.43 after? If I'm wrong I would really appreciate being pointed in the right direction.