Physics
posted by Marc on .
Wheel A of radius ra = 13.9 cm is coupled by belt B to wheel C of radius rc = 34.3 cm. Wheel A increases its angular speed from rest at time t = 0 s at a uniform rate of 5.7 rad/s2. At what time will wheel C reach a rotational speed of 168.2 rev/min, assuming the belt does not slip?

The product of rotational speed and radius is the same for each wheel. So is the product of angular acceleration and radius. Use those facts to deduce the time required.

ok..so for c: v = w*r = 168.2*0.343m =57.6926
and therefore for a: w = v/r = 57.6926/0.139m = 415.055
is that correct?
and for the acceleration:
for a: a= 5.7*0.139 = 0.7923
and for c: 0.7923/0.343 = 2.3099
but how do I get time ?? 
I thought I told you that before.
To get the time, divide the angular velocity change by the angular acceleration