A particle of mass 10 g moves along a circle of radius 6.4 cm with a constant tangential acceleration. What is the magnitude of this acceleration if the kinetic energy of the particle becomes equal to 8 × 10⁻⁴ J by the end of the second revolution after the beginning of the motion?

0.1 m/s²

KE : \(\frac{1}{2}mv^2 = 8 × 10^{-4}\)

m = 10 x 10^-3 kg

v²= 16 x 10^-12

⇒ v = 0.4 m/s

Eq. of motion : \(v^2 = u^2 + 2aS\)

S = 6.4 x 10^-2 m ; u = 0

∴ 0.4 × 0.4 = 2 × a × 2\(\pi\) × 6.4 ×10^-2 × 2

⇒ a = 0.1 m/s²