AIIMS2017Physics-Circular Motion

AIIMS 2017 Physics Centripetal Force and Acceleration MCQ Question

Type: MCQ-conceptual-Medium-Class 11

The particle of mass m is moving in a circular path of constant radius r such that its centripetal acceleration aₚ is varying with time t as aₚ = k²rt², where k is a constant. The power delivered to particle by the force acting on it is

A

2πmk²r²t

B

mk²r²t

C

1/3 mk⁴r²t⁵

D

Zero

Correct Answer

Option B

Detailed Explanation

To find the power delivered to the particle, we first determine the tangential acceleration ata_t using the relationship between centripetal acceleration apa_p and the radius rr. Given ap=k2rt2a_p = k^2 r t^2, we can express the tangential velocity vv as v=rωv = r \omega where ω\omega is the angular velocity. The tangential acceleration ata_t can be derived from the change in vv, leading to at=dvdt=k2rta_t = \frac{dv}{dt} = k^2 r t. The power PP is then calculated as P=Ftv=matv=m(k2rt)(rω)=mk2r2tP = F_t v = m a_t v = m (k^2 r t) (r \omega) = mk^2 r^2 t, confirming option B.

Options A and C are incorrect because they either miscalculate the relationship between force, acceleration, and velocity or introduce unnecessary variables, while option D is incorrect as there is indeed power being delivered due to the tangential acceleration.

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