question_answer

A particle is moving along a circular path of radius \[5\,\,m\] 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                 \[T=\frac{\pi r}{v}=\frac{\pi \times 5}{5}=\pi \]second Hence, average acceleration when particle completes half revolution                 \[{{a}_{av}}=\frac{\Delta v}{T}=\frac{10}{\pi }m/{{s}^{2}}\]