Two objects collide and bounce off each other. Linear momentum does which of the following:?

Question

A. is conserved only if the enviroment is frictionless
B. definetly not conserved
C. definetly is conserved
D. is conserved only if the collusion is elastic

Answer 1

Momentum is a conserved quantity, meaning that the total momentum of any closed system (one not affected by external forces) cannot change.

D. is conserved only if the collusion is elastic
A perfectly elastic collision is defined as one in which there is no loss of kinetic energy in the collision. An inelastic collision is one in which part of the kinetic energy is changed to some other form of energy in the collision. Any macroscopic collision between objects will convert some of the kinetic energy into internal energy and other forms of energy, so no large scale impacts are perfectly elastic. Momentum is conserved in inelastic collisions, but one cannot track the kinetic energy through the collision since some of it is converted to other forms of energy. Collisions in ideal gases approach perfectly elastic collisions, as do scattering interactions of sub-atomic particles which are deflected by the electromagnetic force. Some large-scale interactions like the slingshot type gravitational interactions between satellites and planets are perfectly elastic.

Answer 2

The law of conservation of momentum (linear) is applicable only if the two interacting mass structures are perfectly elastic.
That means they bounce off each other without any power loss.

In perfectly Elastic collison all the conservation laws apply= Conservation of mass(No mass loss),conservation of Time,and conservation of Energy and conservation of Power.
There is only one case where this scenario applies. In General relative motion of mass structures ,mass changes occur(mass loss) during collision.
See Einstein relativity theory on mass change of mass structures in motion.

Therefore the statement in "D' is correct.

Answer 3

C. I have no idea why all these seemingly learned answerers chose D unless they misread the question. (A case of "collusion" maybe?) Momentum is conserved even in completely inelastic, friction-dominated collisions. Read up on it at the ref. page.

Answer 4

D. is conserved only if the collision is perfectly elastic.

B, and C are useless options lol
And A is not correct because friction is not considered anywya as only the momentum just a minute instant before impact and just after impact is equated.

Answer 5

answer is D, the meaning conserved is the energy should be in the system only when the collision is not elastic the energy goes out of the system, hence energy is not conserved if it is a non elastic collision