What are the laws of conservation of momentum, conservation of angular momentum, and conservation of energy? For each, give an example of how it is important in astronomy. Law of conservation of...
Momentum= the total momentum of interacting objects cannot change as long as no external force is acting on them.. aka. Total momentum is conserved.
Ex. Reps Newton's 1st law of constant motion b/c there's no net forces in space to affect things. Therefore, objects must continue to move exactly as they have been moving.
Ex. 2. When you jump off the ground, you actually push the Earth backwards, but its huge mass renders no acceleration.
Angular momentum= As long as there is no external torque, "twisting force," the total angular momentum of a set of interacting objects cannot change.. Both orbital and rotational
Ex. Earth's angular momentum= (m X v X r) mass, velocity/radius of orbit.
Ex. Basically, as long as Earth isn't transferring any of its angular momentum of orbit or rotation to another object, it keeps orbiting and rotating at the same rate.
Energy= Energy cannot appear out of nowhere or disappear into nothing. They can only gain/lose energy by exchanging it with something else.
Ex. Everything that's happened in the universe has been caused by an exchange of energy and matter.
Ex. 2. Planetary interiors cool with time b/c they radiate energy into space
Ex. 3. Sun became hot b/c of energy released by the gas that formed it.