Question

A person of mass $60kg$ is inside a lift of mass $940kg$ and he presses the button on the control panel. The lift starts moving upwards with an acceleration of $1{m/s}^2$. If $g=10{m/s}^2$, the tension in the supporting cable is

• A. $8600\text{N}$
• B. $9680\text{N}$
• C. $11000\text{N}$
• D. $1200\text{N}$

Answer 1

The correct option is C $11000\text{N}$

We first draw the FBD of the given system
and from the newtons equation $F=ma$ we get,

$T-(M+m)g=(M+m)a$
$\Rightarrow T=(M+m)(g+a)=1000\times 11=11000N$