1. BELLWORK 9/10/15 HOW MANY SIG FIGS ARE IN THE FOLLOWING MEASUREMENTS?
A) m
B) 5.00g
C)1250m
D) 105g
E) 3500m

2. Chapter 2-1 Displacement and Velocity

3. Point A --------> Point B
Frame of Reference
- In order to measure the distance of an object we must use a frame of reference.
Point A > Point B
- These are usually distinct points on the Earth's surface or distinguishing points in the sky.

4. Displacement is the shortest distance between the starting point and the ending point.
A change in position
Δ x = xf - xi

5. Turn to Page 41 in your books
What is the gecko’s displacement in Figure 2?

6. Displacement vs. Distance
If the gecko in Figure 2 traveled from the 24.5 cm mark to the 85.5 cm mark
Displacement = 61.0 cm and Distance = 61.0cm
BUT
If the gecko traveled from the 24.5 cm to the 85.5 cm, and returned back to the 24.5 cm mark
Displacement = 0 and Distance = cm

7. Round trips
If you return to the starting point (round trips) the displacement will always be = 0.
Displacement is: How far away you are from where you started.

8. What is the runners Displacement? Distance?

9. Displacement can be + or (-)
See Table 1 on Page 42
To the right , east, upward, or north = Positive
To the left, west, downward, or south = Negative

10. Velocity is speed in
a given direction

11. What is this Gazelle’s velocity?

12. Units
**The SI units for measuring velocity is Meters/seconds **Velocity has to have a direction **Velocity can be either positive or negative (depending on the displacement value)

13. Units Displacement – SI unit for length is meters
Time – SI Unit for time is seconds
Speed (Velocity) – SI unit is m/s.

14. Vavg = Δx = xf – xi
Δt = tf – ti

15. Speed vs. Velocity
Velocity is a vector quantity that has a magnitude (numerical value) and a direction.
Speed has no direction (scalar quantity)

16. Instantaneous Velocity
The velocity at an instant of time

17. Classwork
Page 44 #’s 1-6