question_answer

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

A) \[\frac{10}{\pi }m/{{s}^{2}}\]

B) \[10\,m/{{s}^{2}}\]

C)  \[10\pi \,m/{{s}^{2}}\]

D)  zero

Correct Answer: A

Solution :

 Change in velocity when the particle completes half revolution is \[\Delta v=5-(-5)\] \[=10\,m/s\] Time taken in completing half revolution is \[T=\frac{\pi r}{v}=\frac{\pi \times 5}{5}=\pi \text{second}\] Hence, average acceleration when particle completes half revolution \[{{a}_{av}}=\frac{\Delta v}{T}=\frac{10}{\pi }\,m/{{s}^{2}}\]