Elastic Collisions

Key Questions

• What are some examples of elastic collisions?

  billiard balls
  Newton's cradle
  curling rocks
  shuffleboard pucks
  bowling ball and pins

  Always take time to think because in real-life situations, most collisions are a combination of elastic and inelastic.

  Amory W. · · Aug 24 2014
• Question #15adf

  `m_1, m_2` be the two bodies
  `u_1, v_1` be initial and final velocities of `m_1`
  `u_2,v_2` be initial and final velocities of `m_2`

  let the initial velocity of `m_2` = o. So, `u_2` = 0.

  As the collision is elastic, Kinetic Energy and Momentum are conserved.

  Initial Momentum is `m_1u_1`
  Final Momentum is `m_1v_1+m_2v_2`

  So, `m_1u_1 = m_1v_1+m_2v_2`
  `rArr` `m_1u_1-m_1v_1=m_2v_2`
  `rArr` `m_1(u_1-v_1)=m_2v_2` `->` Equation'1'

  Initial Kinetic Energy is `1/2m_1u_1^2`
  Final Kinetic Energy is `1/2m_1v_1^2+1/2m_2v_2^2`

  So, `1/2m_1u_1^2 = 1/2m_1v_1^2+1/2m_2v_2^2`
  `rArr` `m_1u_1^2 = m_1v_1^2+m_2v_2^2`
  `rArr` `m_1u_1^2-m_1v_1^2 = m_2v_2^2`
  `rArr` `m_1(u_1^2-v_1^2) = m_2v_2^2`
  `rArr` `m_1(u_1-v_1)(u_1+v_1) = m_2v_2^2`

  From Equation '1', `m_1(u_1-v_1)=m_2v_2`

  `rArr` `m_2v_2(u_1+v_1)=m_2v_2^2`
  `rArr` `u_1+v_1=v_2`

  Now, `v_2=u_1+v_1`

  From Equation '1', `m_1(u_1-v_1)=m_2v_2`

  So, `m_1(u_1-v_1)=m_2(u_1+v_1)`
  `rArr` `m_1u_1-m_1v_1=m_2u_1+m_2v_1`
  `rArr` `v_1= (u_1(m_1-m_2))/(m_1+m_2)`

  now, solve the equation '1' using `v_1=v_2-u_1` to get `v_2`

  I think, `v_2=(2m_1u_2)/(m_1+m_2)`

  Final momentum of of `m_1` is `m_1v_1` and Final momentum of `m_2` is `m_2v_2`

  :D

  PS : Sorry if the math is clumsy, I'm new here.

  Shiva Reddy · 2 · Oct 24 2014
• What is an elastic collision?

  Answer:

  Elastic collision is the collision where there occurs no loss in net kinetic energy as the result of collision.

  Explanation:

  Total Kinetic energy before the collision= Total kinetic energy after the collision

  For example,

  Bouncing back of a ball from the floor is an example of elastic collision.

  Some other examples are:-
  `=>`collision between atoms
  `=>`collision of billiard balls
  `=>`balls in the Newton's cradle... etc.

  Reyan Roberth · 1 · Jun 4 2018

• What is the relationship between elastic collisions and kinetic energy?
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• Is the impulse a vector quantity?
• Is the impulse a force?
• Why is the center of mass important in physics?
• During a collision, does an object always encounters an impulse and a change in momentum?
• The collision between a tennis ball and a tennis racket tends to be more elastic in nature than a collision between a halfback and linebacker in football. Is that true or false?
• How can I prove an elastic collision?
• How does the center of mass change position?
• The kinetic energy of an object remains constant during an elastic collision. Is that true or false?
• What are some examples of elastic collisions?
• Question #8effb
• How is the elastic collision equation derived?
• Question #9f171
• 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 1.10 m/s along a line making an angle of 29.0° with its original direction of motion, and the second ball has a speed ?
• On a touchdown attempt, a 95.0 kg running back runs toward the end zone at 3.75 m/s. A 111 kg linebacker moving at 4.10 m/s meets the runner in a head-on collision. If the two players stick together, what is their velocity immediately after the collision?
• A block(1) of mass, m1= 3.2 kg, moving at speed 0.85 m/s hits another block (2) m2=2.7 kg at rest. After collision, both blocks stick and slide together on frictionless surface at the same speed. how to find the ratio of Kinetic energy (final/initial) ?
• How do ik if a question is an elastic collision or inelastic collision? How do i distinguish the difference between them when i am given a question on the test?
• Question #7574f
• A ball with a mass of `2 kg` is rolling at `1 m/s` and elastically collides with a resting ball with a mass of `3 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `2 kg` is rolling at `3 m/s` and elastically collides with a resting ball with a mass of `3 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `3` `kg` is rolling at `3` `ms^-1` and elastically collides with a resting ball with a mass of `3` `kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `3 kg` is rolling at `3 m/s` and elastically collides with a resting ball with a mass of `1 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `2 kg` is rolling at `3 m/s` and elastically collides with a resting ball with a mass of `1 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `2 kg` is rolling at `5 m/s` and elastically collides with a resting ball with a mass of `1 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `2 kg` is rolling at `6 m/s` and elastically collides with a resting ball with a mass of `1 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `2 kg` is rolling at `7 m/s` and elastically collides with a resting ball with a mass of `1 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `2 kg` is rolling at `12 m/s` and elastically collides with a resting ball with a mass of `1 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `2 kg` is rolling at `9 m/s` and elastically collides with a resting ball with a mass of `1 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `2 kg` is rolling at `2 m/s` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `2 kg` is rolling at `4 m/s` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `2 kg` is rolling at `7 m/s` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `2 kg` is rolling at `3 m/s` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `2 kg` is rolling at `9 m/s` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `3 kg` is rolling at `15 m/s` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `3 kg` is rolling at `11 m/s` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `3 kg` is rolling at `1 m/s` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `3 kg` is rolling at `2 m/s` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `3 kg` is rolling at `4 ms^-1` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `3 kg` is rolling at `8 m/s` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `8 m/s` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `1 m/s` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `3 m/s` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `5 m/s` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `7 m/s` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `14 m/s` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `12 m/s` and elastically collides with a resting ball with a mass of `4 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `12 m/s` and elastically collides with a resting ball with a mass of `2 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `2 m/s` and elastically collides with a resting ball with a mass of `2 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `3 m/s` and elastically collides with a resting ball with a mass of `2 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `5 m/s` and elastically collides with a resting ball with a mass of `2 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `9 m/s` and elastically collides with a resting ball with a mass of `2 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `8 m/s` and elastically collides with a resting ball with a mass of `2 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `18 m/s` and elastically collides with a resting ball with a mass of `2 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `18 m/s` and elastically collides with a resting ball with a mass of `3 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5` `kg` is rolling at `4` `ms^-1` and elastically collides with a resting ball with a mass of `3` `kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `6 m/s` and elastically collides with a resting ball with a mass of `3 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `6 m/s` and elastically collides with a resting ball with a mass of `9 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `2 kg` is rolling at `6 m/s` and elastically collides with a resting ball with a mass of `9 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `2 kg` is rolling at `2 m/s` and elastically collides with a resting ball with a mass of `9 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `2 kg` is rolling at `5 m/s` and elastically collides with a resting ball with a mass of `9 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `3 kg` is rolling at `5 m/s` and elastically collides with a resting ball with a mass of `9 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `3 kg` is rolling at `12 m/s` and elastically collides with a resting ball with a mass of `9 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `3` `kg` is rolling at `18` `ms^-1` and elastically collides with a resting ball with a mass of `9` `kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `6 kg` is rolling at `18 m/s` and elastically collides with a resting ball with a mass of `9 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `6 kg` is rolling at `18 m/s` and elastically collides with a resting ball with a mass of `3 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `6 kg` is rolling at `24 m/s` and elastically collides with a resting ball with a mass of `3 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `6 kg` is rolling at `7 m/s` and elastically collides with a resting ball with a mass of `3 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `6 kg` is rolling at `7 m/s` and elastically collides with a resting ball with a mass of `8 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `6 kg` is rolling at `2 m/s` and elastically collides with a resting ball with a mass of `8 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `6 kg` is rolling at `6 m/s` and elastically collides with a resting ball with a mass of `8 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `3 kg` is rolling at `6 m/s` and elastically collides with a resting ball with a mass of `8 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `3 kg` is rolling at `16 m/s` and elastically collides with a resting ball with a mass of `8 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `3 kg` is rolling at `16 m/s` and elastically collides with a resting ball with a mass of `1 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `6 kg` is rolling at `16 m/s` and elastically collides with a resting ball with a mass of `1 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `6 kg` is rolling at `25 m/s` and elastically collides with a resting ball with a mass of `1 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `6 kg` is rolling at `25 m/s` and elastically collides with a resting ball with a mass of `2 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `3 kg` is rolling at `25 m/s` and elastically collides with a resting ball with a mass of `2 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `23 kg` is rolling at `25 m/s` and elastically collides with a resting ball with a mass of `2 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `2 kg` is rolling at `25 m/s` and elastically collides with a resting ball with a mass of `2 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `2 kg` is rolling at `12 m/s` and elastically collides with a resting ball with a mass of `9 kg`. What are the post-collision velocities of the balls?
• A ball with a mass of `5 kg` is rolling at `12 m/s` and elastically collides with a resting ball with a mass of `9 kg`. What are the post-collision velocities of the balls?
• Question #dffe3
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• A block of metal wheighing 2 kg is resting on a frictionless surface,if struck by a jet releasing water at the rate of 1kg/s and at a speed of 5m/s.what is the initial acceleration of the block ?
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• Question #6d21b
• Collision question?