Question

A car with 80cm diameter wheel starts from rest accelerates uniformly to a speed of 15 m/s in 30 second. Through How many revolutions did each wheel turn in this time?

Answer 1

dv/dt = acceleration = 15m/s / 30s = 0.50 meters/s
v = at = 0.50 * 30
x = (1/2) a t^2 = 0.25 (30)^2 = 225 meters
circumference = pi d = 3.14* 0.80 =2.51meters /revilution
so
225 / 2.51 = 89.6 meters

Answer 2

I mean 89.5 revolutions :)

Answer 3

first find the acceleration : a = (V - u)/t = 0.5 m/s2
the next step is finding the velocity : V = a.t = 15m/s
then the distance covered by the car : S = 1/2 . at2 = 225m
then the next step is finding the circumference of the wheel : C = 2x 3.14 x r = 2.51m/rev
then for the distance covered 225m the wheel revolved is : 225/2.51 = 89.6 revolution