The balance wheel of a watch is a thin ring of radius 0.95 cm and oscillates with a frequency of 3.10 Hz. If a torque of 1.1x10-5 Nm causes the wheel to rotate 45°, calculate the mass of the balance wheel.
The Attempt at a Solution
I got an answer but it's wrong...
Here's the work I did:
19.5 rad/s = sqrt (7.003e-6/(M(0.0095m)2))
380.25 rad/s2 = 7.003e-6 Nm / 9.025e-5m M
M*0.0343 m/s2 = 7.003e-6 Nm
m = 2.04e-4 kg
The answer should be 0.41g
(I realized just now that I took the square root of a negative number earlier. I tried to redo the problem but I'm still stuck...) Thanks!