(adsbygoogle = window.adsbygoogle || []).push({}); 1. A mass attached to a 50-cm long string starts from rest and is rotated 40 times in 1.00 min before reaching a final angular speed. Determine the angular acceleration of the mass, assuming that it is constant.

W = Delta Theta/Delta Time

Average Acceleration = Delta W/Delta time

W = Wo + at

Theta = Wo(t) + 1/2at^2

W^2 = Wo^2 + 2a(Theta)

3. I started by finding W. It said that the wheel made 40 revolutions in 1 minute so i put:

40 Rev/60 s : 2(pi)/rev

and from this i got: 4.2 Rad/s

Using this i used the formula W = Wo + at:

4.2 = 60a

.07 rev/s^2 = A

the answer in the book says .14 rad/s^2 can anyone point out my mistake?

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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