NOTE: I know this seems like quite a bit, but it's really not! Most of the questions involve simple 1-line equations, so please don't be discouraged by the amount of text - any assistance is greatly appreciated :) 1. The problem statement, all variables and given/known data A 6kg steel ball moving at 4m/s hits a 6kg putty ball, initially at rest, and sticks to it. After the collision the two move on (stuck together) at 2m/s. a) What is the kinetic energy of the metal ball before the collision? b) What is the kinetic energy of the metal ball after the collision? c) What is the kinetic energy of the putty ball after the collision? d) How much energy does the metal ball 'lose' as a result of the collision? (fixed) e) How much kinetic energy is transferred from the metal ball to the putty ball? f) What happened to the rest of the energy? Explain. Also, there's a second segment which reads: A coconut falls out of a tree 8m above the ground and hits a bystander, 1.75m tall, in top of his head. It bounces up 0.5m before falling back towards the ground. If the mass of the coconut is 2kg, calculate the potential energy of the coconut relative to the ground at each of the following times: a) While it's still in the tree b) When it hits the bystander's head c) When it bounces to its maximum height 2. Relevant equations Ek=0.5mv^2 Eg=mgh 3. The attempt at a solution 1. a) For part 1, I figured out that kinetic energy of the metal ball (prior to collision) was 48J. I'm fairly confident in this answer. :) 1. b) and c) After the collision, however, I calculated the kinetic energy of the metal ball and the putty ball to both be 12J ( 0.5*6kg*2m/s^2). Can they actually both be the same? 1. d) If that's the case, then would the metal ball's 'lost' energy be equal to 48J-12J=36J? 1. e) If the putty ball has a kinetic energy of 12J, then I'm fairly confident that the metal ball transfers 12J of kinetic energy. 1. f) Not sure about this one. Er, I know that some of the energy will be transformed into heat (by friction) and sound, but our teacher was hinting at something involving the change in shape of the putty. Can someone expand on this please? :) PART 2 2. a) Eg=mgh, so Eg=(2)(9.81)(8). I'm fairly confident with this :) 2. b) When it hits the bystander on the head would I simply change the height to 1.75m? So Eg=(2)(9.81)(1.75)? 2. c) Not sure about this one. Would I just add 0.5m to the height of 1.75m? Eg=(2)(9.81)(2.25)? Thank you!