Answer:
The ball's angular displacement after 1.24 seconds is 13.0 rad
Explanation:
The ball's angular velocity is
ω = Δθ/Δt
Since the ball completes 2 revolutions in 1.20 s and each revolution corresponds to an angular displacement Δθ =2π. Thus,
ω = (2(2π rad)/1.20 s
= 10.5 rad/s
The ball moves with a constant angular velocity, so its angular displacement at 1.24 s is
θ_f = θ_i + ωΔt
θ_f = 0 rad + (10.47 rad/s)(1.24 s)
θ_f = 13.0 rad