Question

Calculate the amount of work done by a labourer who carries n bricks ,each of mass m ,to the roof of a house of height h by climbing up a ladder??

Answer 1

Hi friend here is your answer

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We know work done=-P. E.

So, P. E. = mgh, for 1 brick

Now, For n brick P. E. =n×mgh

So, work done= nmgh ans.

where, g=acceleration due to gravity.

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Answer 2

Answer: W = - n m g h

Given data states that a laborer carries n bricks to a height h each of mass m. Therefore the work done will be given by the expression that is,

                          W = - Potential Energy ( P. E. )

Thereby, Potential energy is given by,

                          P. E. = m g h

$\Rightarrow$ For each brick, we have P. E. = m g h and thereby for n bricks will be P. E. = n m g h

$\Rightarrow$ Therefore, the work done is W = - n m g h,

where negative indicates work done against gravity, n is the number of bricks, m is the mass of each brick, g is the acceleration due to gravity and h is the height of the roof of the house.