Question

A person of mass $60\text{kg}$ is inside a lift of mass $940\text{kg}$ and presses the button on control panel. The lift starts moving upwards with an acceleration $1.0{\text{m/s}}^2$. If $g=10{\text{m/s}}^2$, the tension in the supporting cable is

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

Answer 1

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

Net upward force
$\Rightarrow T-60g-940g=ma$
$T-1000g=1000a$
$T=1000(g+a)$
$T=1000\left(11\right)$
$T=11000\text{N}$