ME 203 Homework


Homework 8

How should we go about doing the kinematics for Problem 2?
United States
It's very similar to the problem that we did in class (and from problem 3 on the last homework). You can relate the motion of the tractor at A to the motion of the pulley at "C", which is stationary in terms of a frame of reference fixed in the ground but moving in a frame of reference fixed in the cable. Then the motion of the block can be determined from the motion of the pulley with respect to the cable.

For problem 3 do we use the velocity and acceleration equations for a point fixed in a non moving body or a point fixed in a moving body?
United States
Unfortunately I cannot answer this question without knowing which points you are talking about and in what frame of reference you are trying to relate the points. I typically start with the most general equations and then determine what the individual are for that problem.

For this problem, consider the contact point between the two links, say "P". Then "P" is fixed in the rotating link but moving in the link that translates along the surface. Note that the angular velocity of the sliding link is zero, but the general velocity equations still hold.