The tub of a washer goes into its spin-dry cycle, starting from rest and reaching an angular speed of 6.0 rev/s in 12.0 s. At this point the person doing the laundry opens the lid, and a safety switch turns off the washer. The tub slows to rest in 11.0 s. Through how many revolutions does the tub turn during this 23 s interval? Assume constant angular acceleration while it is starting and stopping in revolutions.

Answer 1

The average velocity during slowdown is 3rev/s

during spinup, it goes: 3rev/sec*12 sec
during slowdown, it goes:3rev/sec*11sec