Answer:
6.0 rev/s gives greater speed for the ball.
Step-by-step explanation:
given,
rotate a ball at the rate of = 8 rev/s
length of chain = 0.6 m
length increase to = 0.9 m
ball able to rotate = 6 rev/s
(a) v = ω R
when R = 0.60 ω = 8×2π
v = 0.60 × 8 × 2π = 30.16 m/s
when R = 0.90 ω = 6.00 × 2π
v = 0.90 × 6.00 × 2π = 33.93 m/s
hence, 6.0 rev/s gives greater speed for the ball.