Inelastic Collisions
Purpose: To gather evidence that can be used to support a claim that total system momentum is or is
not conserved in an inelastic collision.
Background: The objects involved in a collision are often considered as a system. Provided that the
system of two objects is not experiencing a net external impulse, there would be no change in
momentum of the system. If one object within the system loses momentum, it is gained by the other
object within the system. The combined momentum of both objects would be conserved.
Getting Ready: Navigate to the Collision Carts Interactive in the Physics Interactives section of The
Physics Classroom website:
http://www.physicsclassroom.com/Physics-Interactives/Momentum-and-Collisions/Collision-Carts
Path:
physicsclassroom.com => Physics Interactives => Momentum and Collisions => Collision Carts
Once the Interactive opens, resize it as desired. Select the Inelastic Collisions option. Experiment with
changing the Mass and the Initial Velocity of the two carts. Observe how the position of the carts
along the track can be changed by dragging. Learn to Start, Pause, and Reset the animation.
Collision 1: Blue Cart Initially at Rest
Set the initial blue cart velocity to 0 m/s. Set the mass values to different values. Run the simulation
and record the mass and velocity values.
Before Collision After Collision
mRed = _3________ kg mBlue = ___2______ kg
Use mass and velocity values to complete the following momentum table.
Before Collision After Collision ΔMomentum
Red Cart
____3___kg x ___5____m/s
= _______15_____kg•m/s
____3____kg x ___5____m/s
= ____15________kg•m/s
Blue Cart
___2_____kg x ___0____m/s | _____2______kg x __0_____m/s
= ______0______kg•m/s | = ______0____ kg . m/s
System Total
5kg x 5m/s | 5kg x 5m/s
Collision # 2
v = _____3___ m/s | v=____1_____ m/s
MRed=___3___kg | mBlue=____2____ kg
Use mass and velocity values to complete the following momentum table.
Before Collision | After collision
Red Cart
___3____kg x ___3___m/s | ___3____kg x __2.2__m/s
= _____9_____kg•m/s | = ______6.6___kg•m/s
Blue Cart
___2____kg x ___1___m/s | ___2___kg x ___2.2___ m/s
= _____2______kg•m/s | =_____4.4___kg•m/s
System Total
=5kg x 4m/s | = 5kg x 4.4 m/s
Conclusion
Make a Claim as to whether momentum is conserved or not conserved. Identify the Evidence that
provides support for your claim; refer to specific sets of values in each data table that serve as credible
evidence. Write a paragraph or more of sound Reasoning to argue why the evidence logically lead to
the claim you are making. Write well. Write logically. Write thoroughly. Use a separate page of paper
if necessary.
Purpose: To gather evidence that can be used to support a claim that total system momentum is or is
not conserved in an inelastic collision.
Background: The objects involved in a collision are often considered as a system. Provided that the
system of two objects is not experiencing a net external impulse, there would be no change in
momentum of the system. If one object within the system loses momentum, it is gained by the other
object within the system. The combined momentum of both objects would be conserved.
Getting Ready: Navigate to the Collision Carts Interactive in the Physics Interactives section of The
Physics Classroom website:
http://www.physicsclassroom.com/Physics-Interactives/Momentum-and-Collisions/Collision-Carts
Path:
physicsclassroom.com => Physics Interactives => Momentum and Collisions => Collision Carts
Once the Interactive opens, resize it as desired. Select the Inelastic Collisions option. Experiment with
changing the Mass and the Initial Velocity of the two carts. Observe how the position of the carts
along the track can be changed by dragging. Learn to Start, Pause, and Reset the animation.
Collision 1: Blue Cart Initially at Rest
Set the initial blue cart velocity to 0 m/s. Set the mass values to different values. Run the simulation
and record the mass and velocity values.
Before Collision After Collision
mRed = _3________ kg mBlue = ___2______ kg
Use mass and velocity values to complete the following momentum table.
Before Collision After Collision ΔMomentum
Red Cart
____3___kg x ___5____m/s
= _______15_____kg•m/s
____3____kg x ___5____m/s
= ____15________kg•m/s
Blue Cart
___2_____kg x ___0____m/s | _____2______kg x __0_____m/s
= ______0______kg•m/s | = ______0____ kg . m/s
System Total
5kg x 5m/s | 5kg x 5m/s
Collision # 2
v = _____3___ m/s | v=____1_____ m/s
MRed=___3___kg | mBlue=____2____ kg
Use mass and velocity values to complete the following momentum table.
Before Collision | After collision
Red Cart
___3____kg x ___3___m/s | ___3____kg x __2.2__m/s
= _____9_____kg•m/s | = ______6.6___kg•m/s
Blue Cart
___2____kg x ___1___m/s | ___2___kg x ___2.2___ m/s
= _____2______kg•m/s | =_____4.4___kg•m/s
System Total
=5kg x 4m/s | = 5kg x 4.4 m/s
Conclusion
Make a Claim as to whether momentum is conserved or not conserved. Identify the Evidence that
provides support for your claim; refer to specific sets of values in each data table that serve as credible
evidence. Write a paragraph or more of sound Reasoning to argue why the evidence logically lead to
the claim you are making. Write well. Write logically. Write thoroughly. Use a separate page of paper
if necessary.