Question

A circular disc is rotating with constant angular velocity ω about an axis that passes through the centre. A particle 'P' is kept at a distance of 2m from the centre and another particle 'Q' at a distance of 3m from the centre.

Which of these will have higher centripetal acceleration?

• A. P
• B. Q
• C. both have equal
• D. can't say until value of ω is given

Answer 1

The correct option is B

Q

If a particle goes in a circle with constant ω then it has a centripetal acceleration given by ${\omega }^{2}R$ since ω is constant for both particles. So the acceleration depends on R

$\because R_Q>R_P$
$\Rightarrow {\omega }^2{R}_Q>{\omega }^2{R}_P$

So particle q will have higher centripetal acceleration.