Answer the following

1. What is the kinetic energy of a wagon of mass 15 kg whose momentum is 60 kg .m/s? [2 marks] 2. A sledge hammer has a mass of 4.0 kg and is moving down at a speed of 6.0 m/s when it strikes a fence post, driving it 10 cm farther into the ground. What is the magnitude of the average force exerted on the fence post by the hammer? [2 marks] 3. A 10.0-kg toy motorized boat uses 8 W of power, accelerates from rest and reaches a certain speed in 10 s on a horizontal surface. What was that final speed? [3 marks] 4. A block of mass 2.5 kg is sliding across a smooth, level surface at 3.0 m/s when it hits a stationary spring bumper, fixed at one end as shown, whose force constant is 360 N/m. By what amount does the block compress the spring, before coming to rest? [3 marks] 3.0 m/s 2.5 kg 5. A golf club exerts an average force of 7200 N on a ball for the 0.0005s they are in contact. If the ball has a mass of 45 g, what velocity will it have as it leaves the club face? [2 marks] 6. A 12000 kg railroad car is coasting along a level, frictionless track at a constant speed of 25 m/s, when a 3000 kg load is dropped vertically onto the car from above. What will its new speed be, assuming the load stays on the car? [3 marks] 7. A 2000 kg car travelling east at 24 m/s enters an icy intersection and collides with a 3600 kg truck travelling south at 10 m/s. If they become coupled together in the collision, what is their velocity immediately after impact? [4 marks]8. Two carts, of mass 4.5 kg and 1.0 kg, are moving towards each other along the same straight, level track at 2.0 m/s to the right and 4.0 m/s to the left, respectively. Their collision is cushioned by a elastic spring between them. If the force constant of the spring is 900 N/m, what is its maximum compression during the collision? [5 marks] 9. A 4.0 kg ball moving to the right at 5.0 m/s collides head-on with a 2.0 kg ball moving to the left at 4.0 m/s. If the collision is elastic, determine the direction and speed of each ball after the collision. [6 marks] 4.0 kg 5.0 m/s 4.0 m/s 2.0 kg O- V1 O M 2