6.4 POWER 9F2

Write your Full name and class section 1. _ is defined as the rate at which work is done. speed power efficiency mechanical advantage 2. What is the unit for power? hp J W all of the above 3. What unit is watt? joule•second newton•meter joule newton 4. Which of the following is the correct formula for power? P = W P = Fd P = Fv all of the above 5. How much power is required to do 180 J of work in 2.4s? 7.5 W 75 W 75 kW 7.5 kW 6. How much power is required to lift a 20N chair 0.30m in 5s? 3.0 W 2.4 W 1.2 W 0.8 W 7. In a period of 10 seconds, an elevator lifts a weight of 1000 N a distance of 10 m at constant velocity. What is the average power of the elevator over this time? 0 W 100 W 1000 W 10000 W 8. At a given point, a force of 20 N acts on a particle with velocity of 5 m what is the power exerted by the force? 4 W 5 W 20 W 100 W