vector presentation

Vectors

Glenbrook South High School Physics

A scalar is a quantity with magnitude only

1.6 m

34 m/s

A vector is a quantity with magnitude and direction

0.9 m @ 35° N of E

21 m @ 65° E of N

Method 1: Graphical Method

N

S

W E

You travel 6 m @ 35° E of N

And then go 8 m due E

A = 6 m @ 35° E of N

B = 8 m due E

Scale: 1 cm = 1 m

Method 1: Graphical Method

N

S

W E

You travel 6 m @ 35° E of N

And then go 8 m due E

A = 6 m @ 35° E of N

B = 8 m due E

Scale: 1 cm = 1 m35°

Method 1: Graphical Method

N

S

W E

You travel 6 m @ 35° E of N

And then go 8 m due E

A = 6 m @ 35° E of N

B = 8 m due E

Scale: 1 cm = 1 m35°

Sketch a new coordinate axis to make vector B

A

B

Method 1: Graphical Method

N

S

W E

You travel 6 m @ 35° E of N

And then go 8 m due E

A = 6 m @ 35° E of N

B = 8 m due E

Scale: 1 cm = 1 m

23°

A

B

R = 12.5 m @ 23⁰ N of E

E of N 23 @ 5.12 om

Method 2: Component

Method

N

S

W E

A = 6 m @ 35° E of N

B = 8 m due E 35°

A

Ax

Vector X-component

Y-component

A 3.44 m 4.91 m

B

Total

Ay

Method 2: Component

Method

N

S

W E

A = 6 m @ 35° E of N

B = 8 m due E 35°

A

Ax

Vector X-component

Y-component

A 3.44 m 4.91 m

B

Total

Ay

mmAA

xx 44.3)6)(35(sin

6m35sin

mmAA

xy 91.4)6)(35(cos

6m35cos

Method 2: Component

Method

N

S

W E

A = 6 m @ 35° E of N

B = 8 m due E 35°

A

B

Vector X-component

Y-component

A 3.44 m 4.91 m

B 8.00 m 0.00 m

Total

mBx 8

mBy 0

Method 2: Component

Method

N

S

W Eθ

Rx = 11.44m

Vector X-component

Y-component

A 3.44 m 4.91 m

B 8.00 m 0.00 m

Total 11.44 m 4.91 m

Ry = 4.91m

Method 2: Component

Method

N

S

W Eθ

Rx = 11.44m

Ry = 4.91m

mmmR 45.12)91.4()44.11( 22

o

m

m2.23)

44.11

91.4(tan 1

E of N 2.23 @ 45.12 om