physics

posted by .

In a game of pool, the cue ball strikes another ball initially at rest. After the collision, the cue ball moves at 4.15 m/s along a line making an angle of -25° (i.e. below the x-axis) with its original direction of motion (the x-axis), and the second ball has a speed of 2.846 m/s.
Find the angle between the direction of motion of the second ball and the original direction of motion of the cue ball. Assume the masses are equal.

Find the original speed of the cue ball.


Is kinetic energy conserved?

  • physics -

    According to the law of conservation of linear momentum
    vector(p)= vector(p1)+ vector(p2),
    Let vector( p) is directed along +x-axis. Then vector (p1) is
    below x-axis and vector(p2) is above it.
    Projections on axes are
    x: v = v1•cosα +v2•cosβ
    y: 0 = - v1•sin α +v2•sinβ
    sinβ = v1•sin α/v2 = 0.616.
    β = arcsin 0.616 = 38 degr.
    cos β = 0.788.
    v = 4.15•0.906+2.846•0.788=6 m/s.
    At elastic collision the kinetic energy is conserved.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    In a game of pool the cue ball strikes another ball of the same mass and initially at rest. After the collision the cue ball moves at 3.50 m/s along a line making an angle of 22 degrees with its original direction of motion. and the …
  2. physics

    In a game of pool the cue ball strikes another ball of the same mass and initially at rest. After the collision the cue ball moves at 3.50 m/s along a line making an angle of 22 degrees with its original direction of motion. and the …
  3. Physics

    In a game of pool the cue ball strikes another ball of the same mass and initially at rest. After the collision the cue ball moves at 3.50 m/s along a line making an angle of 22 degrees with its original direction of motion. and the …
  4. Physics

    In a game of pool the cue ball strikes another ball of the same mass and initially at rest. After the collision the cue ball moves at 3.50 m/s along a line making an angle of 22 degrees with its original direction of motion. and the …
  5. Physics

    In a game of pool the cue ball strikes another ball of the same mass and initially at rest. After the collision the cue ball moves at 3.50 m/s along a line making an angle of 22 degrees with its original direction of motion. and the …
  6. physics

    In a game of pool, the cue ball strikes another ball of the same mass and initially at rest. After the collision, the cue ball moves at 3.10 m/s along a line making an angle of 27.0° with its original direction of motion, and the …
  7. Physics HELP HELP

    A cue ball traveling at 4.0 m/s makes a glancing, elastic collision with a target ball of equal mass that is initially at rest. The cue ball is deflected so that it makes an angle of 30° with its original direction of travel. (a) …
  8. college physics

    A cue ball initially moving at 4.3m/s strikes a stationary eight ball of the same size and mass. After the collision, the cue ball’s final speed is 2.3 m/s at angle 1 with respect to it's original line of motion. The 8 ball moves …
  9. physics

    A cue ball initially moving at 2.6 m/s strikes a stationary eight ball of the same size and mass. After the collision, the cue ball’s final speed is 1.3 m/s.Find the cue ball’s angle θ with respect to its original line …
  10. Impulse and Momentum

    In the game of billiards, all the balls have approximately the same mass, about 0.20 kg. The cue ball moving west with a speed of 4.5m/s strikes another ball at rest. After the collision the cue ball moves at an angle of 55degree north …

More Similar Questions