question_answer

Find the work done in lifting 4 cement bags, each of mass 50 kg to the top of a building of height 20 m.

Answer:

Given, mass of each cement bag is 50 kg. Therefore, mass of four cement bags                                 \[\Rightarrow \]                 \[\frac{K{{E}_{2}}}{K{{E}_{1}}}=\frac{P_{2}^{2}}{P_{1}^{2}}\] We know, \[\Rightarrow \] \[K{{E}_{2}}={{\left( \frac{2P}{P} \right)}^{2}}\times K{{E}_{1}}\] \[=4\,K{{E}_{1}}\]