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A person can carry 20 bricks at a time. Each brick weighs 10 N. If he takes 50 s to carry 20 such bricks to a distance of 100m, what is his power?

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A person can carry 20 bricks at a time. Each brick weighs 10 N. If he takes 50 s to carry 20 such bricks to a distance of 100m, what is his power?


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Solution:

First, we calculate the power required to carry one brick and then calculate for 20 bricks.

Weight of each brick (F) = 10 N,

Distance covered (d) = 100 m,

Time taken to cover the distance (t) = 50 s

Now, power = \(\frac Wt\)   [ ∵ power is the rate at which work is done ]

= \(\frac{F\times d}t\)

= \(\frac{10\times100}{50}\)

= \(\frac{1000}{50}\)

= 200 W

Now, power required to carry 20 such bricks will be 20 × 200 W = 400 W.

Things to remember from Power
  • The rate of work done per second is called power. Power is also defined as the rate of conversion of energy. Power is measured in watts (W).
  • If 1 Joule of work is done in 1 Sec, the power is said to be 1 Watt.
  • The power of engines is also measured in Horse Power (HP). 1HP = 746Watt
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