Homework H4.M - Fa22

Problem statement
Solution video

DISCUSSION THREAD

Discussion and hints:

Recall the following four-step plan outline in the lecture book and discussed in lecture:

Step 1: FBD
Draw a free body diagram of the system made up of A+B.

Step 2: Kinetics (linear impulse/momentum and work/energy)
From your FBD above, what is the external force acting on the system of A+B in the horizontal direction? What does this say about the linear momentum of this system in that direction? Also, are there any non-conservative forces acting on the system of A+B? What does this say about the mechanical energy of the system?

Step 3: Kinematics
At position 2, B is moving only in the horizontal direction. There is no vertical component of velocity of B at position 2.

Step 4: Solve
Solve for the speeds of A and B from the above equations.


Any questions?

2 thoughts on “Homework H4.M - Fa22”

  1. I got a positive answer for vB and a negative answer for vA, but it seems that at position 2 the signs should be flipped as the ball A is moving in +x and block B is moving -x? Did anyone else also get this?

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