| Problem statement Solution video |
DISCUSSION THREAD
Any questions??
Discussion
FOUR-STEP PLAN
Step 1: FBD - Draw individual free body diagrams (FBDs) of each particle, along with an FBD of both particles together.
Step 2: Linear impulse/momentum - Carefully consider each FBD above. In which directions (if any) is linear momentum conserved for each FBD.
Step 3: Kinematics - None needed here.
Step 4: Solve - Use the conservation of linear momentum equations from Step 2, along with the coefficient of restitution equation in the "n"-directions for the impact to solve for the post-impact velocities.
NOTE: Since e = 0, the "n"-components of velocity of A and B after impact should be equal. Can you see this in the animation above of the impact simulation?
Since particle A is travelling with a direction that is not parallel to particle B but there is no force in the j direction, is it safe to assume that this would mean that particle B would not move in the j direction after impact?
Look at the FBD of B during impact. There is no force acting on B in the t-direction. Therefore since B has no initial velocity component in the t-direction, it will not have a t-component after impact.