Question

A cyclist starts from centre $O$ of a circular park of radius $1\, km$ and moves along the path $OPRQO$ as shown in figure. If he maintains constant speed of $10\,ms^{-1}$, what is his acceleration at point $R$ ?

• A. $10\,ms^{-2}$
• B. $0.1\,ms^{-2}$
• C. $0.01\,ms^{-2}$
• D. $1\,ms^{-2}$

Answer 1

Answer: (B)

The acceleration at point $R$ is towards the centre of the circle.
Here, $v = 10\,ms\,{}^{-1}$,
$r = 1\,km = 1000\,m$
Centripetal acceleration, $a_{c}=\frac{v^{2}}{r}$
$=\frac{\left(10\,ms^{-1}\right)^{2}}{1000\,m}$
$=0.1\,ms^{-2}$