Question

A shaft initially rotating at 1725 rpm is brought to rest uniformly in 20s. The number of revolutions that the shaft will make during this time is
A. 1680
B. 575
C. 287
D. 627

Answer 1

`0=omega_(0)-alphat`
`thereforealpha=(omega_(0))/(t)=((2pi)(1725//60))/(20)`
`=9rad//s^(2)`
`theta=(1)/(2)alphat^(2)=(1)/(2)xx9xx(20)^(2)=1800rad`
`N=(theta)/(2pi)=287`