Elastic and Inelastic Collisions

In summary, elastic collisions result in no loss of kinetic energy, while inelastic collisions result in a decrease in the total kinetic energy of the system. The final velocities in an elastic collision can be calculated using the conservation of momentum and kinetic energy equations. The outcome of an inelastic collision is affected by the masses and velocities of the objects involved, as well as the degree of stickiness or elasticity between the objects. Inelastic collisions can be perfectly inelastic if the objects stick together after the collision. The coefficient of restitution for an inelastic collision can be calculated using a formula involving the initial and final velocities of the objects.
  • #1
BMWPower06
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0

Homework Statement


Which of the following statements are true about elastic and inelastic collisions?
True False for elastic collisions, linear momentum is conserved but kinetic energy is not
True False for inelastic collisions, neither linear momentum nor kinetic energy is conserved
True False for inelastic collisions, both linear momentum and kinetic energy are conserved
True False for elastic collisions, linear momentum is not conserved but kinetic energy is
True False for elastic collisions, both linear momentum and kinetic energy are conserved
True False for inelastic collisions, linear momentum is conserved but kinetic energy is not



The Attempt at a Solution


Answers are in bold, basically this seems really simple i just can't figure out what I am doing wrong. I am applying each one as if it were a car accident and that's what i got. Unfortunately the program doesn't tell me which ones are wrong, only that the answer is wrong, can anyone help me out?

Thanks.
 
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  • #2
BMWPower06 said:

Homework Statement


Which of the following statements are true about elastic and inelastic collisions?
True False for elastic collisions, linear momentum is conserved but kinetic energy is not
True False for inelastic collisions, neither linear momentum nor kinetic energy is conserved
True False for inelastic collisions, both linear momentum and kinetic energy are conserved
True False for elastic collisions, linear momentum is not conserved but kinetic energy is
True False for elastic collisions, both linear momentum and kinetic energy are conserved
True False for inelastic collisions, linear momentum is conserved but kinetic energy is not



The Attempt at a Solution


Answers are in bold, basically this seems really simple i just can't figure out what I am doing wrong. I am applying each one as if it were a car accident and that's what i got. Unfortunately the program doesn't tell me which ones are wrong, only that the answer is wrong, can anyone help me out?

Thanks.

Are the bold answers your answers or the supposedly correct ones? because they don't look right to me.

In short: in ALL collisions the momentum is conserved. In eleastic collisions the kinetic energy is also conserved whereas in inelastic collisions the KE is not conserved (but the momentum is still conserved)
 
Last edited:
  • #3


I can confirm that the following statements are true about elastic and inelastic collisions:

1. False. For elastic collisions, both linear momentum and kinetic energy are conserved.
2. False. For inelastic collisions, both linear momentum and kinetic energy are not conserved.
3. True. For inelastic collisions, both linear momentum and kinetic energy are conserved.
4. False. For elastic collisions, both linear momentum and kinetic energy are conserved.
5. True. For elastic collisions, both linear momentum and kinetic energy are conserved.
6. False. For inelastic collisions, both linear momentum and kinetic energy are conserved.

It is important to note that in both types of collisions, total energy (including potential energy) is always conserved. In elastic collisions, the objects bounce off each other with no loss of energy, while in inelastic collisions, some energy is lost due to deformation or heat.
 

1. What is the difference between elastic and inelastic collisions?

In an elastic collision, there is no loss of kinetic energy, meaning that the total kinetic energy of the system before the collision is equal to the total kinetic energy after the collision. In an inelastic collision, there is a loss of kinetic energy, resulting in a decrease in the total kinetic energy of the system.

2. How do you calculate the final velocities in an elastic collision?

The final velocities in an elastic collision can be calculated using the conservation of momentum and kinetic energy equations. The equations are:
m1v1i + m2v2i = m1v1f + m2v2f (conservation of momentum)
1/2m1v1i2 + 1/2m2v2i2 = 1/2m1v1f2 + 1/2m2v2f2 (conservation of kinetic energy)
Where m is mass and v is velocity.

3. What factors affect the outcome of an inelastic collision?

The factors that affect the outcome of an inelastic collision include the masses and velocities of the objects involved, as well as the degree of stickiness or elasticity between the objects. In general, larger masses and slower velocities result in a more inelastic collision, while smaller masses and higher velocities result in a more elastic collision.

4. Can an inelastic collision be perfectly inelastic?

Yes, an inelastic collision can be perfectly inelastic, meaning that the two objects stick together after the collision and move as one. This occurs when the degree of stickiness or elasticity between the objects is very high.

5. How do you calculate the coefficient of restitution for an inelastic collision?

The coefficient of restitution for an inelastic collision can be calculated using the formula:
e = v2f - v1f / v1i - v2i
Where v is velocity and the subscripts 1 and 2 represent the two objects involved in the collision.

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