Kl. A 1200kg car travelling initially at x = 25.3m/s in an easterly direction crashes into the back of a BSDOkg truck moving in the same direction at \"u = 20.1m/s. The velocity of the car immediately after the collision is W3 = 18.?m/s to the east. 4 v ? "C: q T! -.- i..- ..- Balfou- Afler a) What is the velocity of the truck immediately after the collision? [2 points] b) What is the change in mechanical energy of the car-truck system in the collision? [3 points] K2. A grenade of mass 1.2kg is at rest on a smooth frictionless surface. After the grenade explodes, a 0.50kg piece flies off to the north at 3.0m/s, and a second piece of mass 0.30kg flies off to the southwest at 4.0m/s. Find the velocity (magnitude and direction) of the third piece of the exploded grenade. [5 points] K3. If a 50 kg gymnast and a 400 kg sumo wrestler each dropped from 1 m above the trampoline, find the final position of each athlete. Assume the trampoline is a simple spring obeying Hooke's law with a k value of 12 000 N/m. [5 points] Cl. Two clay balls of equal mass and speed strike each other headon, stick together and come to rest. Kinetic energy is not conserved. What happened to it? Is momentum conserved? Explain your answer. [3 points] A1. A puck of mass 17:, moving at a speed of V; collides with an identical mass stationary puck. After the collision, one puck moves off at an angle 99; with a speed of V;', and the other puck moves off at an angle quiz with a speed of V2' . i'" a r Ha; so a] What are the speeds v1' and v2' if (pl + up; I 90? Express your answers in terms of V1 and pl. [3 points] 1]] Is the collision inelastic or (totally) elastic? Support your answer with a calculation. [2 points] AZ. A pendulum of mass m and length L. is initially at rest at an angle 6. The pendulum then swings down and collides elastically with a stationary block of mass M and pendulum stops after collision. The block slides along the surface and eventually stops when it encounters a rough patch of length ldl . Assume that m I l.'?kg_. L I 0.80m, 6 I 6?\