The angular speed of a motor wheel is increased from `600"rpm"` to `1200"rpm"` in `4` seconds. Calculate how many revolutions does the engine make during this time.

Explanation

Using `omega = omega_(0)+alpha t`
`alpha = (omega - omega_(0))/(t)`
`omega_(0)=600 rp m=(2pi xx600)/(60)=20 pi rad s^(-1)`
`omega = 1200 rp m=(2pi xx1200)/(60)=40pi rad s^(-1)`
`alpha = (20pi)/(4)=5 pi rad s^(-2)`
Again using.
`theta = omega_(0)t+(1)/(2)alpha t^(2)`
`theta = 20 pixx 4+(1)/(2)xx 5pi xx 16`
`theta = 80pi + 40pi = 120 pi`
Number of revolutions `= (theta)/(2pi)=(120pi)/(2pi)=60` revolutions.