Recent content by Yafa

  1. Y

    Determining revolution using Angular Motion

    your angular acceleration looks like you took the second angular velocity and divided it by the entire time of motion. Realize that angular acceleration can only occur if there is torque about that axis. The problem here is that you have two sources of torque: 1. applied force 2. friction...
  2. Y

    Determine mass of a glider on an air track

    The tensions are equal
  3. Y

    What angle do the springs make with the vertical at equilibrium?

    good thinking, but I think you may be using the wrong approach. Think about what the use of the word "equilibrium" implies about the sum of the FORCES. The way I read that question is it is asking you the angle the springs make once the entire system has come to rest (i.e. no longer bouncing...
  4. Y

    Dynamics: Finding distance to reach balance point of a wheelie.

    for anyone who looked at this and is curious, here is an update. I thought this would be a straightforward dynamics problem given all the assumptions; however, it turns out to be something beyond the scope of what is solvable in a beginning dynamics course. The reason is the variable moment...
  5. Y

    Solving Static Equilibrium at Point A: 15 kip/ft & 11 ft

    what are you confused about? What have you done so far?
  6. Y

    Solving for Angular and Linear Velocities in a Two Car Collision

    I think you have to treat each body separately. you have a net loss of energy since your coefficient of restitution is less than 1. You should break up the collision into 3 parts. Find the energy before, the change during, and the energy after the collision. Check this out, it should be of...
  7. Y

    Solving for Angular and Linear Velocities in a Two Car Collision

    I*omega is also equal to r X mv.
  8. Y

    Solving for Angular and Linear Velocities in a Two Car Collision

    More generally, the integral of the sum of all the forces acting on the body over time is equal to the net change in momentum. This can be broken down into component vectors. integral of sigma Fdt = delta G Likewise, the integral of all the moments applied over time is equal to the net...
  9. Y

    Solving for Angular and Linear Velocities in a Two Car Collision

    mv + integral of F dt from t=0 to t=t is equal to mv final. Since V(bp1y) is zero and V(bp2y) is known, V(bp2y) must equal the vertical component of impulse (integral of Fdt). Then use H(A1) + integral of Mdt from t=0 to t equals H(A2). H(A1) = 0 since it isn't rotating, so integral Mdt =...
  10. Y

    Solving for Angular and Linear Velocities in a Two Car Collision

    If you have V(bpy), that should be equal to and opposite the impulse applied to point p on A. Use the principle of impulse and momentum to find omega(A)
  11. Y

    Solving for Angular and Linear Velocities in a Two Car Collision

    do you have V(by)?
  12. Y

    Solving for Angular and Linear Velocities in a Two Car Collision

    OK, I'm thinking that the I.C.R. must be perpindicular to both velocity vectors for the body correct? If you look at the direction of the velocity of P on A just after the collision, there is only one way to draw a perpindicular line to that vector so that you could draw another perpindicular...
  13. Y

    Solving for Angular and Linear Velocities in a Two Car Collision

    you could also try to get V(A) by using the parallel axis theorem and working backwards to get it. Find I about P, then work backwards from there.
  14. Y

    Solving for Angular and Linear Velocities in a Two Car Collision

    right. Have you tried using the relative velocity equations? V(A2) = V(P2) + V(P/A2) V(P/A2) = r (P/A) X omega (P/A) since they are rigid bodies, then omega (P/A) should be the same omega for the entire body...
  15. Y

    Solving for Angular and Linear Velocities in a Two Car Collision

    what do you have so far?