Physics – Quick Reference Sheet

Motion and Force Electricity and Magnetism


Scalar — quantity without direction, only magnitude
Vector — quantity with both magnitude and direction
Velocity — change in position over change in time
Acceleration — change in velocity over change in time
Force — action that causes change in motion
Angular Velocity — change in angle over change in time
Centripetal Force — force towards center of circular motion

Inverse Square Laws — force is inversely proportional to the square of distance
Conservation of Momentum — total momentum of an isolated system is constant
Conservation of Energy — total energy of an isolated system is constant
Newton’s Laws of Motion

First Law — An object in motion remains in motion unless acted upon by an unbalanced external force.
Second Law — The sum of the forces acting on a body equals the mass of the body times its acceleration (F=ma)
Third Law — For every action, there is an equal and opposite reaction.
Kinematic Equations

a=\frac{v-v_0}{t-t_0} v=\frac{x-x_0}{t-t_0} a=\frac{v^2}{r} x=x_0+v_0t+\frac{1}{2}at^2
v=v_0+at v^2=v_0^2+2a(x-x_0) v=\omega r
Momentum and Energy

Momentum — mass times velocity
Forms of Energy — kinetic, gravitational, thermal, chemical, nuclear, electromagnetic, and mechanical
Kinetic Energy — energy associated with velocity
Gravitational Potential Energy — energy associated with height

Elastic collision — energy and momentum are conserved
Inelastic collision — momentum is conserved
Energy transfer — energy changes from one form to another (some energy becomes heat)

K=\frac{1}{2}mv^2 \mathrm{\frac{work}{change in time}} \mathrm{PE=mgh}
SI Units

Quantity Unit Name Symbol Quantity Unit Name Symbol
Time Seconds s Length Meters m
Mass Kilograms kg Volume Cubic Meters m^3
Charge Coulombs C Pressure Pascals Pa
Temperature Degrees Celsius or Kelvins _{K}^{^{\circ} C} Density Kilogram per cubic meters \frac{\mathrm{kg}}{\mathrm{m^3}}

Quantity Definition Symbol Units Unit Symbol
Electric Charge Produces electric field q Coulombs C
Electric Force
– Two types of charge (positive and Negative)
– Like charges repel
– Opposite charges attract
Magnetic Force
– Magnetic charge does not exist
– Force is produced by moving electric charge

Electric Motors — use Ampere’s Law to convert electric energy into mechanical energy
Electric Generator — use Faraday’s Law to convert mechanical energy into electric energy


Faraday’s Law — changing electric field produces magnetic field
Ampere’s Law — electric current produces magnetic field
Coulomb’s Law — electric force is proportional to electric charges and inversely proportional to distance squared

Coulomb’s Law
Magnetic Force

Electric Force

Resistors in Series
I is constant
Resistors in Parallel
V is constant
Ohm’s Law
Electric Power
Fundamental Constants

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