Vectors

Ms. Juanita Larraín-Linton

Scalars and Vectors

SCALAR

-Refers to a MAGNITUDE...

Example: Speed

10 m/s

Scalars and Vectors

VECTOR

-Refers to a MAGNITUDE AND ITS DIRECTION...

Example: Velocity

10 m/s South

Example

Mass

Ammount

of matter

Weight

(Force)

Attraction

of an

ammount

of matter

to the Earth

Scalar: 150 Kg Vector: 1500 N

ADDING SCALARS

Scalars only refer to QUANTITIES only:

We must add these quantities as numbers:

+ +

0.5 L + 0.5 L + 0.5 L 1.5 L

ADDING VECTORS

Vectors refer to both QUANTITIES and DIRECTION:

We must add them both....

HOW?

If both vectors are in the same line....

10 N + 4N

14N

If both vectors are in the same line but opposite....

10 N + 4N

6N

The parallelogram rule

If two vectors are NOT in the same line we must apply this rule.

The parallelogram rule

1. “Transfer” your vector to the end of the other vector. It MUST have the same position (angle) and magnitude (length).

1. Draw your the resulting force.

Pythagoras’ theorem: right angles

For all other

cases, drawing

and measuring

angles and

lenghts is

required

30 N

40 N

50 N

Inclined surfaces