A 55.5 kg man walks up a set of stairs in 10.2 s. The man rises 4.5 m in going up the stairs. What is the average power (in Watts) exerted by the man during the climb?

Same set-up for the conservation of energy was performed. The 5-g marble covered a horizontal distance of 40 cm from the edge of the ramp (horizontal) from an elevation of 15 cm above the ground. At what height (in cm) relative to edge of the ramp was the marble released? Use g=9.8 m/s2. Round off your answer to two decimal places.

88.

2 W S X In a hydroelectric dam, water falls 35 m and then spins a turbine to generate electricity. 3 E D 80 C $ 4 R 888 F V 96 5 T G ^ 6 B ▾ Part A What is AU of 1.0 kg of water? Express your answer with the appropriate units. View Available Hint(s) AU= -340 J Y Submit ▾ Part B ✓ Correct SOLVE: The change in the potential energy of 1.0 kg of water in falling 35 m m is H Suppose the dam is 80% efficient at converting the water's potential energy to electrical energy. How many kilograms of water must pass through the turbines each second to generate 48 MW of electricity? This is a typical value for a small hydroelectric dam. Express your answer in kilograms per second. ▸ View Available Hint(s) m 11s AU, -mgh=-(1.0 kg) (9.8 m/s²) (35 m) = -340 J = = Provide Feedback Submit MacBook Air Previous Answers & 7 N IG] ΑΣΦ | 3-4 U * 8 D-H I M @ JK ( 9 MOSISO DD O I भ ? O L kg/s command F10 P > ; C option + ? T I Next > delete re

Patrick usually walks up three flights of stairs to his physics class without getting tired. However, on Monday, he is late for class and decides to run up the three flights of stairs. Although he did not run for a long period of time and traveled the same distance as normal, Foster feels more tired at the top of the stairs than on the days he walks. Use the concept of power to explain why he feels more tired.

A) A 1390 kg car accelerates uniformly from rest to 10.4 m/s in 2.87 s. Find the work done on the car in this time interval. Answer in units of kJ. B) Find the average power delivered by the en- gine in this time interval. Answer in units of hp. C) Find the instantaneous power delivered by the engine at t = 1.5 s. Answer in units of hp.

Multiple-Concept Example 13 presents useful background for this problem. The cheetah is one of the fastest accelerating animals, for it can go from rest to 31.8 m/s in 3.38 s. If its mass is 119 kg, determine the average power developed by the cheetah during the acceleration phase of its motion. Express your answer in (a) watts and (b) horsepower. (a) Number i (b) Number Units Units

An electron in a television tube is accelerated uniformly from rest to a speed of 8.4 × 107 m/s over a distance of 2.5 cm. What is the power delivered to the electron at the instant that its displacement is 1.0 cm?

A 7.56 kg object is initially traveling in the positive x-direction at a speed of 1.7 m/s. 31.3 seconds later, the object is traveling at a speed of 1.39 m/s in the negative x-direction. How much total work was done on the object during the 31.3 seconds?

Samantha pushes a 113 kgkg crate on a ramp that makes 8.59 degreesdegrees with the horizontal. What is the change in potential energy of this crate after Samantha pushes it for 10.0 mm along the ramp? (The answer choices have 3 significant figures.)