Answer:
616.3 rad/s²
Explanation:
Given that
t= 1.46 s
Initial angular velocity ,ωi = 0 rad/s
Final angular velocity ωf= 27000 rev/min
Angular speed in the rad/s given as

Now by putting the values

ωf=900 rad/s
We know that (if acceleration is constant)
ωf=ωi + α t
α=Angular acceleration
900 = 0 + α x 1.46

Therefore the acceleration will be 616.3 rad/s²
1/f= 1/di+1/do
1/f=1/90m+1/40m
1/f ≈27.7m
Answer:
7.5 right?
Explanation: if im wrong shoot me