1. A 6.0 kg mass is pulled up a 20 m long, 150 ramp at a constant speed of 2.25 m/s. What power is required to do this? 2. A 50 kg child rides down a frictionless 2.5 metre high slide. Find the speed at the bottom of the slide. 3. How much work is done by a person pulling the 8 kg mass across a 20 metre long frictionless floor. As shown below, the person pulls on the rope with 35 N of force. 35N 15 8 kg 4. A 1 100 kg car moving at 30 m/s slows down to 12 m/s. Find the work done by friction. 5. A 2.5 kg mass moving at 3 m/s hits a stationary 1.25 kg mass and sticks to it. Find the speed of the objects after the crash. 6. In #5, find the thermal energy created by the collision. 7. A 80 kg linebacker moving at 4 m/s East hits and sticks to a 60 kg running back moving North at 7 m/s. Write momentum equations 8. In #7, find the final speed and direction if the players stick together. 9. A 6 kg mass moving East at 4 m/s hits an obstacle and after a 0.15 second collision, is moving at 3 m/s and 10 N of E. Write impulse equations to find Fx and Fy force components 10. In #9, find the force of the collision. 1 1. Find the unknown mass M required to balance the metre stick. Note that the metre stick itself has mass 100 grams 60 100 p 75 g12. Write a balanced torque equation you could use to find the force exerted by the ground on the toes of this person in push-up position. CM O 45 cm 30 cm 550 N 13. The diving board pictured below has a mass of 50 kg. The person at the end has a mass of 75 kg. The board has two supports, L and R (left and right). Write a torque equation using the support L as a pivot. 3 metres L R 0.75 metres 14. In #13, write a balanced force equation 15. A mass moving in uniform circular motion has a speed of 4 m/'s and an acceleration of 1.5 m/s2. Find the radius of the circle and the speed of the object after 2 seconds of motion. 16. On a u=0.7 road, what is the maximum safe speed in a 20m radius corner for a 1000 kg car. 17. A roller coaster is upside down at the top of a 4 metre radius loop. To stay on the track, at what speed must the coaster be going? 18. A Ferris wheel of radius 6.5 m is moving at 4.5 m/s. Find the apparent weight of a 55 kg person at the bottom of the ride. 19. Write a force equation for an object in orbit. 20. Find the orbit speed of a 50 kg rock 2000 km above the surface of the Earth