Answer the following questions in paper

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]