Recent content by trogtothedor

I understand that there is energy loss. However, momentum is conserved I thought... which is why conservation of momentum is applied. If that's the case then I don't understand why you can't apply conservation of angular momentum to point P and treat the cars as an entire system.

When I plug the values given to us as the answers into that equation, it does not work. I don't know if the values could be wrong, which they have been in the past, or if I did not set up my angular impulse equation correctly.

Sorry for being so lost. Our book has nothing near as complex as this problem and the most difficult example we solved in class was a simple rod with a fixes point of rotation.

Thank you for you're assistance, but now I am stuck on one final element. I am unsure whether or not I have the correct angular impulse equation about point p. Should it be : m(ra X Va1) + m(rb X Vb1) = I*omega(a) + I*omega(b) + m(ra X Va2) + m(rb X Vb2) ?

Do you mean after impact? I solved for V(B2Y) in terms of the initial and post-collision velocities of A. I'm not exactly sure how to set up the equation that you're taking about

I was trying to do that but kept ending up with nonsense or arriving at the same equations i already had.

and omega(A)

Yes I did that. I had velocities at P in the equation relating to the coefficient of restitution, then i substituted values of the velocity at A in order to remove those unknowns, which left me with V(A2Y).

I can scan the equations that led up to that one if that is helpful. However, I know that they are correct. I used the velocities in the y direction at point P, along with the coefficient of restitution, to arrive at an equation for omega(B) which used omega(A) and V(A2Y). I used conservation...

Also the masses of both cars and the moments of inertia are similar, so m is the mass of either car and I is either cars mass moment of inertia.

As stated, the only unknowns are omega(A) and V(A2Y), which is the velocity of the center of mass of A in the y direction after impact. In the equation, a variable followed by an x or y means that it is the x or y component of that vector. Also, a 1 or 2 denotes pre-collision, 1, and post...

I will upload a picture of my equation since it will be too confusing to type.

Or in your other post, it seems as if the IC is taken to be the center of mass. Both the center of mass and the impact points have non-zero velocities. If I knew the point about which they were rotating, or possibly a component of the velocity at point P, this would be easy. However, I know neither.

Right, but that seems like you're taking the point of impact as the instantaneous center of zero velocity. However, point P for both cars has a non-zero velocity.

I still don't understand. Wouldn't the cross product of Velocity x Distance result in units of meters squared over seconds?