Question

A body is moving in a circle with a speed of $1m{s}^{-1}$. This speed increases at a constant rate of $2m{s}^{-1}$ every second. Assume that the radius of the circle described is $25$ m. The total acceleration of the body after $2s$ is:

• A. $2m{s}^{-2}$
• B. $25m{s}^{-2}$
• C. $\sqrt{5}m{s}^{-2}$
• D. $\sqrt{7}m{s}^{-2}$

Answer 1

The correct option is C $\sqrt{5}m{s}^{-2}$

$a_1=2m{s}^{-2},v=u+a_{1}t=1+2\times 2=5m{s}^{-1}$
$a_c=\frac{v^2}{r}=\frac{5^2}{25}=1m{s}^{-2}$
Net acceleration $=\sqrt{a_c^2+a_t^2}=\sqrt{1^2+2^2}=\sqrt{5}m{s}^{-2}$.