A computer disk drive is turned on starting from rest and has constant angular acceleration.?
a.If it took 0.810 s for the drive to make its second complete revolution, how long did it take to make the first complete revolution?
Express your answer with the appropriate units.
b.What is its angular acceleration, in rad/s2?
a) Θ = ω₀*t + ½αt²
To complete first revolution
2π rads = 0*t + ½αt²
and to complete the first and second combined
4π rads = 0*t + ½α(t+0.810s)²
Divide second by first:
2 = (t + 0.810s)² / t²
This is quadratic in t and has roots at
t = -0.336 s ← ignore
and t = 1.96 s ◄
b) Use either equation from above:
2π rads = 0*t + ½α(1.96s)²
α = 3.27 rad/s² ◄
Hope this helps!
A computer disk drive is turned on starting from rest and has constant angular acceleration.