Question

A body of mass $5\text{kg}$ is raised vertically to a height of $10\text{m}$ by a force $170\text{N}$. The velocity of the body at this height will be

• A. $9.8\text{m/s}$
• B. $15\text{m/s}$
• C. $22\text{m/s}$
• D. $37\text{m/s}$

Answer 1

The correct option is C $22\text{m/s}$

$a=\frac{F-mg}{m}=\frac{170-50}{5}=24m/s^2$
From kinematics equation
$v=\sqrt{2as}$
$=\sqrt{2\times 24\times 10}=21.9m/s\approx 22m/s$