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3 years ago

What is the average power supplied by a 60.0 kg secretary running up a flight of stairs rising vertically 4.0 m in 4.2 s?

Physics

1 answer:

gayaneshka [121]3 years ago

4 0

Answer:

9.8kW

Explanation:

Given data

Mass= 60kg

Hieght= 4m

Time= 4.2seconds

We know that the energy possessed is given as

PE=mgh

PE=60*9.81*4

PE= 2354.4 Joulse

Also, the expression for power is

Power=Energy*Time

Power= 2354.4*4.2

Power=9888.48 watt

Power= 9.8kW

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3 years ago

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Explanation:

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jolli1 [7]

Answer:

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Explanation:

Case 1: Boat 1

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While going to another end

time = $\frac{distance of river}{speed of boat}$

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time = 1 hour

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time = $\frac{distance of river}{speed of boat}$

time = $\frac{48}{48}$

time = 1 hour

Total time taken by boat 1 is,

Total time by boat 1 = 1 hour + 1 hour = 2 hour

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Total time taken by boat 1 for the round trip is 2 hour.

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time = $\frac{distance of river}{speed of boat}$

While going to another end

time = $\frac{distance of river}{speed of boat}$

time = $\frac{48}{24}$

time = 2 hour

While going back,

time = $\frac{distance of river}{speed of boat}$

time = $\frac{48}{72}$

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Total time taken by boat 2 is,

Total time by boat 1 = 2 hour + 0.66 hour

Total time by boat 1 = 2.66 hour

Total time taken by boat 2 for the round trip is 2.66 hour.

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3 years ago

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Answer:

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Explanation:

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