Question

If we lift a body of mass 7 kg vertically upward 10 m, then calculate the force required to lift the body ($g=10m{s}^{-1}$).

Answer 1

Step 1: Data provided,

$$\begin{gathered} mass\left(m\right)=7kg \\ height\left(h\right)=10m \end{gathered}$$

Formula used,

$Force\left(F\right)=mass\left(m\right)\times acceleraton\left(a\right)$

Step 2: Calculation,

The minimum force is required to lift the body should be equal to the force by which the Earth is pulling the body so,

$$\begin{gathered} Requiredforce=Pullforcebyearth \\ =mass\left(m\right)\times accelerationduetogravity\left(g\right) \\ =7kg\times 10m{s}^{-2} \\ =70kgm{s}^{-2} \\ =70N \end{gathered}$$

Hence, the force required to lift the body is $70N$.