Question

A body is moving with a constant speed of $5.5\text{m/s}$ in a circle of radius $5\text{m}$. The net acceleration of the body is

• A. $12.5{\text{ms}}^{-2}$
• B. $6.5{\text{ms}}^{-2}$
• C. $6.05{\text{ms}}^{-2}$
• D. Zero

Answer 1

The correct option is C $6.05{\text{ms}}^{-2}$

Let $a_c$ be the cenripetal acceleration. We know that
$a_c=\frac{v^2}{r}=\frac{{5.5}^2}{5}=6.05{\text{m/s}}^2$

Since the speed is constant, tangential acceleration is zero. So, the only acceleration acting is centripetal acceleration which is the net acceleration

Net acceleration $=\sqrt{a_c^2+a_t^2}=\sqrt{{6.05}^2}=6.05{\text{ms}}^{-2}$

Hence option B is the correct answer.