1. Physics and Measurement

2. Measurements Basic units of measure Length Meter
Mass Kilogram (1kg = 2.2lbs)
Weight Newton (1kg = 10N)
Time Second

4. Scalar vs. Vector Scalar Vector
Measurement that has magnitude (number) 5m
Vector
Measurement that has magnitude and direction
5m, east

5. Scalar vs. Vector Distance Displacement Measurement of length
Measurement of distance in a certain direction
Vector measured from starting point directly to end point

6. Distance vs. Displacement
A person walks 2 miles North, then 4 miles East, and finally 2 miles South.
Distance = 8 miles
Displacement = 4 miles, East

7. Scalar vs. Vector Speed Velocity
Amount of distance traveled in a given amount of time (m/s)
Velocity
Speed in a direction

8. Vectors For Force (weight) Ever Electric Field Strength
At Acceleration
The Torque
D Displacement
M Momentum
V Velocity

10. Vector Components
Vectors can be broken down into horizontal and vertical components
Right Triangles H
Hsinθ θ
Hcosθ

11. Examples Find horizontal and vertical components X = Hcos θ
X = 20cos 30
X = 17.32m
20m Y
Y = Hsin θ
30°
Y = 20sin 30 X
Y = 10m

12. Examples Find horizontal and vertical components X = Hcos θ
X = 4.6cos 60
4.6m
X = 2.3m Y
Y = Hsin θ
Y = 4.6sin 60
60°
Y = 3.98m X

13. Direction
Vectors always have a direction N W E S

14. Direction
What if you don’t know which way is north?
90°
180° 0°
270°

15. Standard Convention
90°
180° 0°
270°

16. Example
A student walks 6m at 0° and then 8m at 90°. What is the resultant displacement? R 8m
R= 10m, 53° θ 6m