Answer:
option (a)
Explanation:
t = 5 sec, α = 2 rad/s^2, f0 = 20 rpm = 20 / 60 rps
Use second equation of motion for rotational motion
θ = ω0 x t + 1/2 α t^2
θ = 2 x 3.14 x 5 x 20 / 60 + 0.5 x 2 x 5 x 5
θ = 10.47 + 25 = 35.47 rad
Number of revolution = 35.47 / (2 x 3.14) = 5.65