__Velocity__ The displacement divided by the elapsed time **v
**= **d** / t

__Acceleration__ The change in velocity divided by the elapsed
time **a** = **v** / t

__Newton's First Law of Motion__

An object continues in a state of rest or in a state of motion at a constant speed along a straight line, unless compelled to change that state by a net force.

__Newton's Second Law of Motion__

When a net force **F** acts on an object m, the acceleration
**a **that results is directly proportional to the net force
and has a magnitude that is inversely proportional to the mass.
The direction of the acceleration is the same as the direction
of the net force. **F** = m **a** N (kg m/s2)

__Newton's Third Law of Motion__

Whenever one body exerts a force on a second body, the second body exerts an oppositely directed force of equal magnitude on the first body.

__Static Frictional Force__

The magnitude **f**s of the frictional force can have any value
from zero up to a maximum **f**smax , depending on the applied
force. u' is the coefficient of static friction and **F** is
the normal force. **f**s = u' **F**

__Kinetic Frictional Force__

The magnitude **f**k of the kinetic frictional force is given
by the relation: **f**k = u **F**

where u is the coefficient of kinetic friction and **F** is
the normal force.

The coefficient of friction is at a maximum when the body is static. When the body is set in motion decreases until it reaches a certain level.

__Linear Momentum__

The linear momentum **p** of an object is the product of the
object's mass m and velocity **v** : **p** = m **v**

__Principle of Conservation of Linear Momentum__

The total linear momentum of an isolated system remains constant(is conserved). An isolated system is one for which the vector sum of the external forces acting on the system is zero.

__Collisions__

A collision is a process involving two objects, each of which
exerts a force on the other. Object 1 exerts a force **F**12
on object 2. Object 2 exerts a force **F**21 on 1.

m1**u**1 + m2**u**2 = m1**v**1 + m2**v**2 (elastic
collisions)

m1**u**1 + m2**u**2 = (m1 + m2)**v** (inelastic collisions)

__Work__ = Force * Distance = **F d** = **W**