# Relationship between momentum and inertia

### kinematics - Inertia Vs Momentum - Physics Stack Exchange

Momentum vs Inertia. Inertia and momentum are two concept involved in the study of motion of solid bodies. Momentum and inertia are used to. Homework Help: Relationship between momentum and inertia car's mass, then it will have more momentum and roll down the ramp faster. Momentum is a function of an object's mass and velocity. . Among them, a plastic chair will have less inertia because it will apply less reaction.

These are statements concerning quantities that, under certain conditions, remain constant or unchanging.

### How it works - Momentum - Momentum and Inertia, Mass and Weight, Velocity and Speed

The conservation of linear momentum law states that when the sum of the external force vectors acting on a physical system is equal to zero, the total linear momentum of the system remains unchanged—or conserved. The conservation of linear momentum is reflected both in the recoil of a rifle and in the propulsion of a rocket through space. When a rifle is fired, it produces a "kick"—that is, a sharp jolt to the shoulder of the person who has fired it—corresponding to the momentum of the bullet.

Why, then, does the "kick" not knock a person's shoulder off the way a bullet would? Because the rifle's mass is much greater than that of the bullet, meaning that its velocity is much smaller. As for rockets, they do not—contrary to popular belief—move by pushing against a surface, such as a launch pad. If that were the case, then a rocket would have nothing to propel it once it is launched, and certainly there would be no way for a rocket to move through the vacuum of outer space.

Instead, as it burns fuel, the rocket expels exhaust gases that exert a backward momentum, and the rocket itself travels forward with a corresponding degree of momentum. Systems Here, "system" refers to any set of physical interactions isolated from the rest of the universe.

Anything outside of the system, including all factors and forces irrelevant to a discussion of that system, is known as the environment. In the pool-table illustration shown earlier, the interaction of the billiard balls in terms of momentum is the system under discussion. It is possible to reduce a system even further for purposes of clarity: Thus, we will ignore the friction of the pool table's surface, and the assumption will be that the balls are rolling across a frictionless plane.

Impulse For an object to have momentum, some force must have set it in motion, and that force must have been applied over a period of time. Likewise, when the object experiences a collision or any other event that changes its momentum, that change may be described in terms of a certain amount of force applied over a certain period of time.

### Inertia, Momentum, Impulse, and Kinetic Energy | omarcafini.info

The resistance to change of motion does not depend upon direction, so it is what we call a "scalar" quantity, and has been named Mass. We quantify Mass using units such as kg or lb-mass.

Objects that require a lot of Force to accelerate a little bit have large Mass. Objects that accelerate a lot with a little bit of Force have small Mass.

## Momentum - How it works

Speed is also a scalar quantity, but when we combine speed with direction, we get a "vector" quantity called Velocity. Momentum has both a magnitude and a direction. We quantify the Momentum of an object as the product of the Mass scalar quantity times its Velocity vector.

Momentum is also a measurable property of a sets of objects. Their individual Momenta can be added together using vector addition and be represented by a virtual object we call a Center of Mass moving with a Net Velocity.

## Homework Help: Relationship between momentum and inertia

Momentum is "conserved", which simply means that it does not change over time for any closed system unless some external force is applied. For a collection of objects, their collective Momentum does not change, even if they bang into each other and bounce apart again or clump together, or one object goes spinning off away from its neighbors. These collisions, if not perfectly elastic, will reduce the Kinetic Energy of the system, especially if they clump together into a single object, but the Momentum of the clump will be the same as the net momentum of all the original individual pieces -- the Center of Mass will continue to move with the same Net Velocity.

While Total Energy is conserved first law of thermodynamicsKinetic Energy can shift into other forms such as Thermal Energy or Potential Energy, so it is not conserved like Momentum.