An object in motion will stay in motion in a straight line, forever, unless acted upon by an unbalanced force.

Half of Newton's First Law

An object at rest will remain at rest unless acted upon by an unbalanced force

The other half of Newton's First Law

If an object is experiencing an unbalanced force, we know that the _________ _____________ is not zero.

Net Force

If objects in motion tend to stay in motion, forever, unless acted upon by a net force, why do we seem to always see objects slowing down on their own?

Friction

(This is the force usually slowing down objects, and it is hard to actually see where the friction is coming from)

Another name for Newton's First Law

Law of Inertia

Inertia means almost the same thing as __________

Mass

Objects with bigger mass have more _________

Inertia

If all the forces on an object are balanced, then there is no net force. In this case, we say the object is in ____________

**Equilibrium**

(Note: An object in equilibrium will have no acceleration, this means it could be either standing still __ OR__ moving along at a constant velocity)

Gravity can apply a ___________

Force

Magnetism can apply a __________

Force

Electrical charges can apply a _________

Force

(Think of static electricity pulling a sock onto your shirt when you take them out of dryer.)

"m" is a unit of

distance

"in" is a unit of

distance

"cm" is a unit of

distance

"miles" is a unit of

distance

"s" is a unit of

time

"s" means "seconds"

"hr" is a unit of

time

"days" is a unit of

time

"m/s" is a unit of

speed

(Units of speed will always have a distance over a time)

"cm/day" is a unit of

speed

(Units of speed will always have a distance over a time)

"mm/yr" is a unit of

Speed

(Units of speed will always have a distance over a time)

"m/s North" is a unit of

Velocity

(notice that it has a direction included)

"mm/yr East" is a unit of

Velocity

(notice that it has a direction included)

"cm/hr West" is a unit of

Velocity

(notice that it has a direction included)

"miles North" is a unit of

Displacement

(Displacement is a vector, so it has both magintude and direction.)

"cm West" is a unit of

Displacement

(Displacement is a vector, so it has both magintude and direction.)

Displacement

Vector or Scaler?

Vector

Velocity

Vector or Scaler?

Vector

Speed

Vector or Scaler?

Scaler

(has only magnitude)

Distance

Vector or Scaler?

Scaler

(Distance has magnitude only)