Question

A particle is moving along a circular path of radius $5m$ with a uniform speed $5m{s}^{-1}$. What will be the average acceleration when the particle completes half revolution?

• A. $Zero$
• B. $10m{s}^{-2}$
• C. $10\pi m{s}^{-2}$
• D. $\frac{10}{\pi }m{s}^{-2}$

Answer 1

The correct option is D $\frac{10}{\pi }m{s}^{-2}$

When the particle completes half revolution change in velocity
$\Delta v=[5-(-5\left)\right]m/s=10m/s$

Time taken to complete the half revolution is
$t=\frac{\pi r}{v}=\frac{\pi \times 5}{5}=\pi s$

Thus, average acceleration $=\frac{\Delta v}{t}=\frac{10}{\pi }m/s^2$.