Question

Calculate the amount of work done in raising a glass of water weighing $2.5kg$ through a height of 40 cm. Take, $g=10m/s2$

Answer 1

Step 1: Given data

Mass of a glass of water is, $m=2.5kg$

The height through which the glass is raised is, $h=40cm=0.4m$

Acceleration due to gravity is to be taken as, $g=10m/s^2$

Step 2: Calculating the amount of work done

When a body is lifted through a certain height, work done is given as,

$W=mgh$

where, $m$ is mass, $g$ is the acceleration due to gravity and $h$ is height.

Substituting the given values, we get,

$$\begin{gathered} W=2.5kg\times 10m/s^2\times 0.4m \\ W=10J \end{gathered}$$

Therefore, the work done is $10J$.