Question

A work of $4900J$ is done on a load of mass $50kg$ to lift it to a certain height. Calculate the height through which the load is lifted.

Answer 1

Step 1: Given,

$\mathit{m}\mathit{a}\mathit{s}\mathit{s}\mathbf{,}\mathbf{}\mathit{m}\mathbf{=}\mathbf{50}\mathit{k}\mathit{g}$

work done, $\mathit{W}\mathbf{=}\mathbf{4900}\mathbf{}\mathit{J}$

Step 2:Finding h

When an object is raised to a height, the work done is equal to the potential energy stored in the body.

Work done = Potential Energy = $\mathit{m}\mathit{g}\mathit{h}$

Substituting the values in the formula

$\mathit{W}\mathbf{=}\mathit{m}\mathit{g}\mathit{h}$

$$\begin{gathered} \mathbf{4900}\mathbf{=}\mathbf{50}\mathbf{\times }\mathbf{9}\mathbf{.}\mathbf{8}\mathbf{\times }\mathit{h} \\ \mathit{h}\mathbf{=}\frac{\mathbf{4900}}{\mathbf{50}\mathbf{\times }\mathbf{9}\mathbf{.}\mathbf{8}} \\ \mathit{h}\mathbf{=}\mathbf{10}\mathit{m} \end{gathered}$$

Therefore, the object is raised to a height of $\mathbf{10}\mathit{m}\mathbf{.}$