Question

A wheel rotates through 5.7 rad in 2.6 s as it is brought to rest with constant angular acceleration. Determine the wheel's initial angular speed before braking began.

Answer 1

Answer: w = 4.38rad/s

Therefore the initial speed is 4.38rad/s

Explanation:

Given;

Angular distance = 5.7rad

Time = 2.6sec

When moving at constant angular acceleration, the angular distance covered can be given as;

d = ((w0 + w1)/2)t .....1

Where d = angular distance = 5.7rad

w = initial angular speed

w1 = final angular speed = 0

t = time of change. = 2.6 s

Substituting to equation 1 we have;

5.7 = ((w+0)/2)×2.6

w = 5.7×2/2.6

w = 4.38rad/s

Therefore the initial speed is 4.38rad/s