If the momentum of one object changes in a system that is subject to no net external force, what else must happen?
1) Collisions with other objects will change its momentum back.
2) The momenta of the other objects in that system change in the same way.
3) The momenta of the other objects in that system are not necessarily affected.
4) The momenta of the other objects in that system change to cancel out the first change.
5) The momenta of the other objects in that system are necessarily not affected.
The total momentum of the system can not change if there is no external force. Therefore 4
The correct answer is option 2) The momenta of the other objects in that system change in the same way.
When an object experiences a change in momentum in a system with no net external force, according to the law of conservation of momentum, the total momentum of the system must remain constant. This means that if one object's momentum changes, the momenta of the other objects in the system must also change.
To determine this, you can use the principle of conservation of momentum, which states that the total momentum of a closed system remains constant if no external forces act on it. Mathematically, this can be expressed as:
Σ(m₁v₁) = Σ(m₂v₂)
Where m₁, v₁ are the mass and velocity of the first object, and m₂, v₂ are the mass and velocity of the second object.
If the momentum of the first object changes, the total momentum of the system must be conserved, necessitating a change in momentum of the other objects within the system. Therefore, the momenta of the other objects in the system change in the same way.