A car whose brakes can produce an acceleration of 3m/s2 is traveling at 10 m/s when its brakes are applied. What is the car's speed 5s later? (10 points) Write down the second law of motion. What is formula for force? (5 points) How many steps are there in a scientific method and list all of them? (5 points) Distinguish between mass and weight. (5 points) 5. A person drops apple from a window and it takes about 10s to reach the ground. Determine the height of the window from the ground. (5 points) 6. a) A horizontal force of 20 N is used to push a 2 kg box 5 meters across a level. How much work we have to do? (b) How much work is needed to raise the same box by 7 m? (10 points) 7. How much power does motor provides an elevator in a building when the total mass when loaded is 500 kg to a height of 3m in 25 seconds? (10 points) 8. (a) What is the KE of a 500 kg car whose speed is 2 meters/sec? (5 points) (b) What is the gravitational potential energy of a 330 kg car on top of a 5 m cliff? (5 points) 9. (a) What is global warming? Give two reasons why global warming is causing sea level to rise? (5 points) (b) What is alternate energy and list few examples of alternate energy? (5 points) 10. What is density and its units? Determine density of 320g of object with a volume of 100cm3? (10 points) Useful Formulas: Vs = Vit ( a. t) 1 h = = gt2 W = F. d or W = m. g.h m. g. h P = t 1 KE = - mv2 PE = m. g. h g = 9.8 m/$2