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# Conservation Laws

A conservation law states that a particular measurable property of an isolated physical system does not change as the system evolves. The physical result concerning conservation laws is Noether’s theorem. This theorem states that there is a one-to-one correspondence between conservation laws and differentiable symmetries of physical systems.

Exact laws are conservation laws that are said to be more precise and never been shown to be violated. A list of exact laws is as followed
- Conservation of mass-energy
- Conservation of linear momentum
- Conservation of angular momentum
- Conservation of electric charge
- Conservation of color charge
- Conservation of weak isospin
- Conservation of probability
- CPT symmetry
- Lorentz symmetry

Approximate conservation laws are approximately true in particular situations. These situations can be low speeds or short time scales.
- Conservation of mass
- Conservation of baryon number
- Conservation of lepton number
- Conservation of flavor
- Conservation of parity
- Invariance under time reversal
- CP symmetry

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## Categories within Conservation Laws

### Conservation of Energy

Solutions: 177

The total amount of energy in an isolated system remains constant over time.

### Conservation of Momentum

Solutions: 162

The total amount of energy in an isolated system remains constant over time.

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### Weight of objects

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### Motion in Straight-Line

Freeway Traffic. According to a Scientific American article (May, 1990), current freeways can sustain about N vehicles per lane per hour in smooth traffic flow at speed . Above that figure the traffic flow becomes "turbulent" (stop-and-go). 1) If a vehicle is of length L on the average, what is the average spacing between ve

### Conservation Laws- Inelastic collison

In an inelastic collision, is the final total momentum more than the initial momentum, less than the initial momentum or is it the same as the initial momentum?

### Final Total Momentum of an Inelastic Collision

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### Linear Momentum and Collisions Question on Rowboats

Two people, one of mass 70 kg and the other of mass 60 kg, sit in a rowboat of mass 80 kg. With the boat initially at rest, the two people, who have been sitting at opposite ends of the boat, 3.0 m apart from each other, exchange seats. How far will the boat move?

### Linear Momentum and the Collision of two Tennis Balls

A 0.060 kg tennis ball, moving with a speed of 7.80 m/s has a head-on collision with a 0.086 kg ball initially moving away from it in the same direction at a speed of 3.10 m/s. Assume a perfectly elastic collision and take the initial direction of the balls as positive. What is the velocity of the tennis ball after the collis

### Elastic Collisions in One-Dimension

A 237g air track glider moving at 0.80m/s on a 2.4 long air track collides elastically with a 513g glider at rest in the middle of the track. The end of the track over which the struck glider moves is not level, but slants upward at an angle of 0.70 degrees with respect to the horizontal. Will the glider reach the end of the tra

### Uniform decceleration: Calculate distance of design to collapse car in a crash

"A person who is properly constrained by an over-the-shoulder seat belt has a good chance of surviving a car collision if the decceleration does not exceed 26.0 G's (1.00 G = 9.8 m/s^2). Assuming uniform decceleration of this value, calculate the distance over which the front end of the car must be designed to collapse if a cras