A flywheel on a motor goes from rest to 1000 rpm in 6 sec. The number of revolutions made is nearly equal to
A flywheel on a motor goes from rest to 1000 rpm in 6 sec. The number of revolutions made is nearly equal to
Right Answer is:
50
SOLUTION
Initial angular velocity, ω₀ = 0 [because flywheel moves from rest ]
Final angular velocity, ω = 1000 rpm = 1000/60 rev/sec
Time taken, t = 6 sec
From Rotational Motion
ω = ω₀ + αt
Where α is angular acceleration.
1000/60 = 0 + α6
α = 1000/360 = 100/36 = 25/9 rev/s²
Now
θ = ω₀t + 1/2αt²
= 0 + 1/2 × 25/9 × (6)²
= 1/2 × 25/9 × 36
= 1/2 × 25 × 4
= 50 rev
Hence, number of revolutions = 50