Physics 20 Laws of Physics

Newton's 1st Law

An object will continue to move or stay at rest until an external outer force acts upon it. (inertia)

Newton's 2nd Law

The acceleration of an object is dependent upon two variables - the net force acting upon the object and the mass of the object. The acceleration of an object depends directly upon the net force acting upon the object, and inversely upon the mass of the object.

Newton's 3rd Law

For every action force there is an equal and opposite reaction force.

Kepler's 1st Law of Planetary Motion

Planets orbit the sun in elliptical orbits with the sun at one focus of the ellipse.

Kepler's 2nd Law of Planetary Motion

A straight line joining the sun to a planet sweeps out equal areas in equal times.

Kepler's 3rd Law of Planetary Motion

Ratio of a planet's orbital period squared to it's orbital radius cubed is a constant. All satellites orbiting the same object have the same constant, so we can set up a ratio.

Hooke's Law

The that the force needed to extend or compress a spring by some distance is proportional to that distance. (Fs=kx)

Snell's Law

Waves that change mediums may result in a changed wavelength and speed. Frequency is not dependent on the medium, but instead it is dependent on the source. (f1=f2)

Doppler Effect

When the true frequency of a source of sound is changed so that the observer hears a different apparent frequency as they move relative to each other.

Law of Conservation

The total mechanical energy in a system remains constant. (Initial E=Final E)

Conservation Law

Energy can be transformed from one form to another and transferred from one object to another, but the total amount remains constant.