Consider a block of mass 5 Kg that follows a circular motion. Its mass decreases at the rate of 0.5 Kg/s. At what time the centripetal force will be zero on the block?
Answer & explanation
Correct answer: option 1
Centripetal force $ \propto $ m
As $m \rightarrow 0$ , $\text{Centripetal force } \rightarrow 0$
m = 5 - 0.5t
m = 0 = 5 - 0.5 t
$\Rightarrow t = \frac{5}{0.5} = 10 s$