Question

An $80kg$ man stands on a spring balance in an elevator. When it start to move, the scale reads $700N$. What is the acceleration of the elevator? $(g=10{ms}^{-2})$

Answer 1

Reading of spring balance $=m(\overrightarrow{g}-\overrightarrow{a})$ where, $\overrightarrow{a}$ is acceleration of elevator

Here, $m(\overrightarrow{g}-\overrightarrow{a})=700N$

$\Rightarrow 80(10-a)=700N$

$\Rightarrow 10-a=\frac{70}{8}$

$\Rightarrow a=10-8.75=1.25m/s^2$