physics
posted by fg on .
A car tire rotates with an average angular speed of 29rad/s.
In what time interval will the tire rotate 3.5 times?
Answer in units of sec.

Answer in m/s.
The speed of a moving bullet can be deter
mined by allowing the bullet to pass through
two rotating paper disks mounted a distance
72 cm apart on the same axle. From the
angular displacement 32.1 of the two bul
let holes in the disks and the rotational speed
862 rev/min of the disks, we can determine
the speed of the bullet.
What is the speed of the bullet?
Answer in units of m/s. 
Answer in revs.
The tub of a washer goes into its spin
dry cycle, starting from rest and reaching an
angular speed of 4.2 rev/s in 4.5 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 12.9 s .
Through how many revolutions does the
tub turn? Assume constant angular accelera
tion while it is starting and stopping.
Answer in units of rev. 
In the Bohr model of the hydrogen atom,
the speed of the electron is approximately
1.97 × 106 m/s.
Find the central force acting on the electron
as it revolves in a circular orbit of radius
4.72 × 10−11 m.
Answer in units of N. 
39.92