- #1
MicahP
- 8
- 0
Homework Statement
Water falls onto a water wheel causing it to rotate. Consider an instant when the water wheel is initially motionless and then 100 kg of water hits tangent to the wheel at a radius of 2 m (this water can be treated like a point mass). If the moment of inertia of the water wheel is 3000 kg∙m2,what is the angular speed of the water wheel immediately after the water has hit it (in rad/s)?
Picture:
Homework Equations
[itex]I=mr^2[/itex]
[itex]KE_r=1/2Iω^2[/itex]
[itex]Ʃ\tau = Iα[/itex]?
The Attempt at a Solution
Well, the first thing I did was find the moment of inertia of the water:
[itex]I_w = 1/2(100kg)(2m)^2 = 200 kg*m^2[/itex]
And then I thought that I should use the kinetic rotational energy equation, but that didn't get me anywhere. I also tried to find a similar problem in my textbook, but there wasn't really anything like it.
I do know the answer is supposed to be 0.29 rad/s, if that helps.