Question

1.If you exert a force of 800 N to walk 3 m up a flight of stairs in 8 s, how much power do you use? *

1 point

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19,200 W

2133 W

30 W

300 W

2.An olympic athlete is training to jump straight up a distance of 1.5 m. How much kinetic energy does the 68kg athlete need to jump this high? (The acceleration due to gravity is 9.8 m/s2.) *

1 point

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0.2 J

999.6 J

10.4 J

444.3 J

3.A 440-g cylinder of brass is heated to 97.0 degrees Celsius (from an initial 26 degrees Celsius) and placed in a calorimeter containing 350 g of water at 23.0 degrees Celsius. The water is stirred, and its highest temperature is recorded as 31.0 degrees Celsius. From the thermal energy gained by the water, determine the specific heat of brass. The specific heat of water is 4.18 J/g x C. (The heat transferred from the brass equals the heat transferred to the water) *

2 points

0.002 J/gxC

2.4 J/gxC

0.42 J/gxC

58.7 J/gxC

4.A force of 15 N is applied to the handle of a screwdriver being used to pry off the lid of a paint can. As the force moves through a distance 0.7 m, the screwdriver does 4.1 J of work on the lid. What is the efficiency of the screwdriver? *

1 point

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39.05%

2.6%

256.1%

5.25%A 200-m long ski lift carries skiers from a station at the foot of a slope to a second station 50 m above. What is the IMA (Ideal Mechanical Advantage) of the lift? *

1 point

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4

1/4

250

10,000

Answer 1

Answer:

power = work done / Time taken

work done = force × distance

= 800× 3

= 2400 J

power = 2400/ 8

power = 300 w

Answer 2

Answer:

300watt

Explanation:

can't answer all at once sis