Suggestions:
- All points on the cable on the right that are not wrapped around the drum have zero speed. Since the drum does not slip on the cable, the speed of point C, therefore, must be ZERO.
- Write down the rigid body velocity equation relating the velocities of points D and C: v_D = v_C + omega x r_D/C. [Since this cable does not slip on the drum, we know that v_A = v_D.] This equation will give you the angular velocity of the drum.
- Write down the rigid body velocity equation relating the velocities of points B and C: v_B = v_C + omega x r_B/C. Use the value of omega found in 2. in this equation to find the velocity of point B.
3 comments:
i am having trouble calculating V_b in this problem. i used V_D = omega x r d/c however my answer is .03 off from the answer given by the book. not sure where the error is because i have reworked it multiple times
Can you give us a little more information on your answers?
--What number are you getting for omega for the pulley?
--What number are you getting for the speed of B?
It might also be rounding error. I know the first time I worked the problem I was a few digits off because I used a value of .3 instead of .3333333 or something like that during the final calculation.
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