Last saved by: Martha Casquette

From The Physics Classroom’s Physics Interactives

http://www.physicsclassroom.com

https://www.physicsclassroom.com/Physics-Interactives/Momentum-and-Collisions/Collision-Carts/Collision-Carts-Interactive

HOE: Momentum Conservation in Explosions

Purpose: To gather evidence that can be used to support a claim that total system momentum is or is not conserved in an explosion.

Background: The objects involved in an explosion 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 Explosions option (at the bottom). Experiment with changing the Mass of the two carts; leave the Initial Velocity at 0 m/s. Observe how the position of the carts along the track can be changed by dragging. Learn to Start, Pause, and Reset the animation.

Explosion 1: Red Cart More Massive than the Blue Cart
<IMPORTANT>Set the initial velocities of both carts to 0 m/s. Set the mass of the red cart to be the greater mass. Run the simulation and record the mass and velocity values.</IMPORTANT>
Before Explosion	After Explosion

At Rest.

v =	m/s

v =	m/s

^mRed ^=	^kg	^mBlue ^=	^kg

Use mass and velocity values to complete the following momentum table.

| Before Explosion | After Explosion | ∆Momentum

Red Cart

kg x	m/s

=	kg•m/s

kg x	m/s

=	kg•m/s

Blue Cart

kg x	m/s

=	kg•m/s

kg x	m/s

=	kg•m/s

System Total | | |

Explosion 2: Red Cart Less Massive than the Blue Cart
<IMPORTANT>Set the initial velocities of both carts to 0 m/s. Set the mass of the red cart to be the smaller mass. Run the simulation and record the mass and velocity values.</IMPORTANT>
Before Explosion	After Explosion

At Rest.

v =	m/s

v =	m/s

^mRed ^=	^kg	^mBlue ^=	^kg
Use mass and velocity values to complete the following momentum table.

| Before Explosion | After Explosion | ∆Momentum

Red Cart

kg x	m/s

=	kg•m/s

kg x	m/s

=	kg•m/s

Blue Cart

kg x	m/s

=	kg•m/s

kg x	m/s

=	kg•m/s

System Total | | |

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 leads to the claim you are making. Write well. Write logically. Write thoroughly. Use a separate page of paper if necessary.