Question

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

• A. zero
• B. $10/\pi m{s}^{-2}$
• C. $10m{s}^{-2}$
• D. None of these

Answer 1

The correct option is B $10/\pi m{s}^{-2}$

As the average acceleration is change in velocity over the time taken,

In this case when the half revolution is over the direction in the speed changes by 180 degrees,

so the change in velocity $=5-(-5)=10$ m/s

The time taken to cover this distance $=\frac{\pi \ast r}{5}=\frac{5\pi }{5}=\pi$ (as the distance travelled is semicircle)

So, average acceleration $=\frac{10}{\pi }m{s}^{-2}$