Question

A particle of mass m is moving in a circular path of constant radius r such that radial acceleration a_r = k²t²r. Find the power delivered to the particle by the forces acting on it.

• A. 2πmk²r²t
• B. mk²r²t
• C. 1/3 mk⁴r²t³
• D. 0

Answer 1

Answer: (B)

mk²r²t

Answer 2

$\frac{v^{2}}{r} = k^{2}t^{2}r$ or

v = ktr F =$\frac{mdv}{dt} = mkr$ and

Power P = $\overrightarrow{F}.\overrightarrow{v}$

P = mkr (t k r) = mk²r²t