Is theta even necessary in this problem for part a since we are not asked to give any type of coordinates? The solution video did not use theta at all.

Hi Kenneth. I don't think theta is necessary because it does not affect the speed of the cables, and thus the ropes in this case which is what we're trying to solve for.

After finding the lengths of the cables and taking the time derivatives, I said that SdotB equals V_B. What would SdotC equal?

KATHERINE: SdotC is the speed of the center of the pulley C, v_C. This is an intermediate result that you can use to relate the velocities of A and B.

Is theta even necessary in this problem for part a since we are not asked to give any type of coordinates? The solution video did not use theta at all.

Hi Kenneth. I don't think theta is necessary because it does not affect the speed of the cables, and thus the ropes in this case which is what we're trying to solve for.