Question

[tex]i) cosecx^{2} 57-tanx^{2} 33°= ?
\\ii)\alpha -\beta = costheta\\[/tex]
iii)only correct

Answer 1

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.