what is law of conservation of momentum?

Answer 1

The principle of conservation of momentum states that the total amount of momentum of all the things in the universe will never change. One of the consequences of this is that the center of mass of any system of objects will always continue with the same velocity unless acted on by a force outside the system.

In an isolated system (one where external forces are absent) the total momentum will be constant: this is implied by Newton's first law of motion. Newton's third law of motion, the law of reciprocal actions, which dictates that the forces acting between systems are equal in magnitude, but opposite in sign, is due to the conservation of momentum.

Momentum has the special property that, in a closed system, it is always conserved, even in collisions. Kinetic energy, on the other hand, is not conserved in collisions if they are inelastic. Since momentum is conserved it can be used to calculate unknown velocities following a collision.

A common problem in physics that requires the use of this fact is the collision of two particles. Since momentum is always conserved, the sum of the momentum before the collision must equal the sum of the momentum after the collision

Answer 2

Hey! Okay, so when I first saw this question I thought, there is no such law. But 'lo and behold there is. Can't believe I forgot. I looked in my old physics text book from high school and did a quick search and this is what I found:

The principle of conservation of momentum states that the total amount of momentum of all the things in the universe will never change. One of the consequences of this is that the center of mass of any system of objects will always continue with the same velocity unless acted on by a force outside the system.
Conservation of momentum is a consequence of the homogeneity of space.

In an isolated system (one where external forces are absent) the total momentum will be constant: this is implied by Newton's first law of motion. Newton's third law of motion, the law of reciprocal actions, which dictates that the forces acting between systems are equal in magnitude, but opposite in sign, is due to the conservation of momentum.

Since momentum is a vector quantity it has direction. Thus, when a gun is fired, although overall movement has increased compared to before the shot was fired, the momentum of the bullet in one direction is equal in magnitude, but opposite in sign, to the momentum of the gun in the other direction. These then sum to zero which is equal to the zero momentum that was present before either the gun or the bullet was moving.

I hope that helps!☃✌

Answer 3

This particular law states that if there is no net external forces acting on a system the momentum of the system will continue to be what it is. This law is a simple deduction from second law which states that the rate of change of momentum is equal to the force applied on the body. So, when you apply no force there is no change in the momentum. Now momentum is mass times velocity,so, this implies that the sysytem always move with same velocity(A body at rest will continue to be at rest while a body with certain velocity will always have that same velocity), unless some net force is applied on the system.

Answer 4

Total momentum is constant in all physical processes. Momentum is usually described as mass times velocity, or "mv". Velocity is a vector, so although speeds are always greater than or equal to zero, a velocity can be negative (if up is the positive direction, then down is the negative direction). If you have a giant rock, it has a momentum. If it is moving, its momentum is not zero, and if it is still its momentum is zero.

In either case, picture the rock floating in space with a stick of dynamite in it. Its momentum is MV, where M is its mass and V is its velocity. If the dynamite blows the rock into a million pieces, and you take the momentum of each piece and add them all together (mv + mv + mv + ...), the total momentum will still be equal to MV. It's kind of spooky (at least I think so), but it's true.

Answer 5

In a closed mechanical system, the sum of all momentum components (mass times velocity) is constant. This applies to billiard balls colliding on a table or gas molecules in a container, as long as no outside forces are acting on the components of the system.

Answer 6

the system must be isolated: the affect of all external forces acting on m1 and m2 must be negligable.
The conservation of momentum holds for a collision involving any number of objects:



Momentum is a vector, and each component is conserved separately. The equation for conservation of momentum really contains three equations, one for each dimension.

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Answer 7

There are sevarals quantities in the nature that are conserved, like energy and mass.

The momentum is one of that quantitie : p = m * v.

Is impossible to provee the conservations laws, are phenomenological events.

Answer 8

Simplified: "a body in motion tends to stay in motion, a body at rest tends to stay at rest."

Answer 9

it makes the earth rotate