gives a quick answer

accuracy limited by drawing skills

**Which way**

you

be goin'?

you

be goin'?

**VECT-ARRRS!!!!**

**Find the buried treasure 5 miles from this screen**

3 feet deep

3 feet deep

**Mission:**

WHY are we doing this?

USS Really?

AHOY! There be TWO

kinds of quantities!

Scalar (italics)=

NO direction

VECTORS (Bold)=

Know which way they be goin'

Time

Mass

Distance

Energy

Displacement

Force

Suppose you weigh out 5.0 g of NaCl. You then add 3.0 g more, and later add 8.0 g more.

Adding Scalars

WHAT DO WE HAVE?

Graphical

Vector Addition

Mathematical

requires knowledge of trigonometry

time-consuming

gives accurate results

Using an appropriate scale, draw each vector using a line segment whose length represents the magnitude and whose arrow shows the direction of the vector:

HEAD TO TAIL

A

B

A

B

+

+

A

-B

+

A

B

A

B

+

?

1 block = 25 m

~53

o

~37

O

A + B = 500 m, 53 N of E

A + B = 500 m, 37 E of N

0

0

A = 2 m, East

B = 3 m, South

C = 4 m, 30 South of West

o

30

o

A

B

C

A + B + C = 5.2 m, 17 West of South

o

OR 253

o

requires use of ruler and protractor

gives a quick answer

accuracy limited by drawing skills

3 Cases:

Parallel

Perpendicular

Neither

**Mathematical**

Simply add/subtract the numbers and go with the direction of the largest number

Case 1: Parallel

300 m East + 100 m East

400 m East + 200 m West

Addition:

Subtraction:

Case 2: Perpendicular

A = 300 m, E

B = 400 m, N

Draw diagram as for graphical method (need not be to scale):

Use Pythagorean Theorem to find magnitude:

Use Trig to find the direction of resultant

C

r

A

Z

y

ANGLES

Every vector can be split into two simple components

12

O

A = 357 m, 12 N of E

o

NOT TO SCALE

**ALAS! We can do real PHYSICS!!!!!!**

ARRRRn't you glad?

ARRRRn't you glad?

**Now for a REAL lab!**