- #1
frostedpoptar
- 15
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Homework Statement
problem #62
Homework Equations
Torque = F * radius
Tangential accel = radius * alpha
w = mg
Kinematic equations for linear motion
The Attempt at a Solution
I tried to find the net torque and go from there.
For clockwise torque I got T = 10 * .25 = 2.5 Nm
For ccw torque I got T = 1.5g * .25 = 3.675 Nm
For net torque I then get ccwT - cwT = 1.175 Nm
I used that with Torque = I * alpha to find alpha.
1.175 = .5 * m * r^2 * alpha
1.175 = .0625 * alpha
18.8 = alpha
Then to get tangential accel I did
Accel = .25 * 18.8
accel = 4.7 m/s^2
Plug that into kinematics
.3 = .5 * 4.7 * t^2
.357 s = t
This is wrong however, the answer is .56 s.
Can anyone tell me where I went wrong? Thanks.