2D Collisions Video Lessons

Example

# Problem: Let two particles of equal mass collide. Particle 1 has initial velocity, directed to the right, and particle 2 is initially stationary. A. If the collision is elastic, what are the final velocities and of particles 1 and 2?B. Now suppose that the collision is perfectly inelastic. What are the velocities and of the two particles after the collision?B. Now assume that the mass of particle 1 is 2m, while the mass of particle 2 remains m. If the collision is elastic, what are the final velocities v1 and v2 of particles 1 and 2?

###### FREE Expert Solution

The momentum of a moving object:

$\overline{){\mathbf{p}}{\mathbf{=}}{\mathbf{m}}{\mathbf{v}}}$

Conservation of momentum:

Conservation of kinetic energy:

A.

The objects separate after the collision.

Using conservation of momentum and the variables m1 = m2 = m, v0,1 = v, v0,2 = 0, vf,1 = v1 and vf,2 = v2.

mv + m(0) = mv1 + mv2

v1 = v - v2 --------- Eqn 1

Using conservation of energy:

(1/2)mv2 = (1/2)mv12 + (1/2)mv22

v2 = v12 + v22 ------- Eqn 2

###### Problem Details

Let two particles of equal mass collide. Particle 1 has initial velocity, directed to the right, and particle 2 is initially stationary.

A. If the collision is elastic, what are the final velocities and of particles 1 and 2?

B. Now suppose that the collision is perfectly inelastic. What are the velocities and of the two particles after the collision?

B. Now assume that the mass of particle 1 is 2m, while the mass of particle 2 remains m. If the collision is elastic, what are the final velocities vand v2 of particles 1 and 2?