Suggestions:
- Look at the FBD of the particle given above. Note that none of the forces acting (mg, T or N) creates a non-zero z-component of moment about point O.
- Therefore, the z-component of the angular momentum about point O is conserved (constant). Use this to find the new value of omega. Note that the value of "r" to be used in finding the angular momentum is NOT equal to "b".
- You can find the work done by T using the work-energy equation: U_1-2 = T_2 - T_1 +V_2 - V_1, where T_1 and T_2 are the kinetic energy of the particle at instances 1 and 2, respectively. With the given information and the results from the angular momentum equation, you can find the change in kinetic energy T_2 - T_1. The change in potential energy can be found from the given information. Be careful with signs in finding the change in potential energy.
3 comments:
Are e_theta and k in the same direction?
I keep getting a large number for the work. Is this the correct equation: 0.5*w2^2 - 0.5*w1^2 + g*h2 - g*h1?
e_theta points out of the page. It's not the same as k.
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