9) Bumpy is on a sled of mass 3500 kg moving at 32 m/s. Lumpy is on a sled of mass 4100 kg moving at 10 m/s. They collide with each other, with the collision softened by a spring of force constant 7.1 MN/m. What is the maximum compression of the spring?

Hint: At maximum compression, they are not moving closer together and not farther apart, so they must be going at the same speed. Use conservation of momentum to find that speed.Use conservation of energy(1/2mv^2=1/2kx^2) to find the compression. Ans:1.1m

6) Xerxes is driving a 2200 kg car and rams into Phiilip who was stopped in his 1500 kg car. She was travelling at 36 km/h before the collision and is moving at 18 km/h afterward. All the lost kinetic energy goes into crushing P's car. It takes 50000 N to crush the car. How much shorter has the car become?

Hint: Use the conservation of momentum to find the speed of Philips car. Use conservation of energy(1/2mv^2=1/2kx^2) to find the compression. Ans :0.84m