You are hired to lift 30 kg crates a vertically 0.90 m from the ground onto a truck. How many crates would you have to load onto the truck in 1 minute for your average power output in lifting the crates to be 100 W

22 crates

Explanation:

Power = Force ×Distance/time taken

Power = m×a×d/t

Power = 30×9.81×0.9/60 (1min was converted to second)

Power = 264.87/60

Power = 4.4145Watts

If my average power output us 100aw, then;

Number of crate to load = average power/4.4145

Number of crates to load = 100/4.4146

Number of crates to load = 22.6

Hence I will have to load about 22 crates onto the truck in 1 minute for my average power output in lifting the crates to be 100 W.

c. magnitude and direction