Question

A man carrying a bag of total mass 25kg climbs up to a height of 10m in 50 seconds. Calculate the power delivered by him on the bag. ( Ans : 49J)

Answer 1

Given conditions ⇒

Mass of the body = 25 kg.

Height = 10 m.

Time = 50 seconds.

Kinetic Energy = mgh

= 25 × 9.8 × 10

= 2450 J

Now,

∵ Power = Energy/Time

∴ P = 2450/50

∴ P = 49 W.

Hence, the Power used by the man is 49 W.

Hope it helps.

Answer 2

Thanks for the question!

It is definitely a very interesting question to solve and do some brainstorming.

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Given,

Mass = 25 kg.

Height = 10 m.

Time = 50 seconds.

We know,

Kinetic Energy = mgh {where m is the mass in kilograms, g is the acceleration due to gravity (9.8 m / s2 at the surface of the earth) and h is the height in meters}

= 25 × 9.8 × 10

= 2450 J

Also,

Power = Energy/Time

P = 2450/50

P = 49 W

1 Watt is defined as 1 Joule per second.

Hence, the Power used is 49 J.

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Hope it helps and solves your query!!