1. Why do we use the word speedometer instead of velocimeter?

2. What would a vector arrow look like for someone traveling 100 km/h, West? 75 km/h, West)

3. Velocity…is it changing? Yes or no?

4. Velocity
Velocity=Δdisplacement = Δx
Time t
= x-x₀
t-t₀
Unit: m/s →

5. Velocity =​−4 m​​/5 s​​ =−0.8​s​​m
An airplane passenger took 5 seconds to move −4 meters, (where the negative sign indicates that displacement is toward the back of the plane.) His average velocity can be written as:
v​avg​​=​​​Δx​​/t
=​−4 m​​/5 s​​
=−0.8​s​​m

6. 2 types of velocity Constant Speed and Constant Direction
What would you have to have to have a constant velocity?
Constant Speed and
Constant Direction
Would that be a straight line or a curved path?

7. 2 types of velocity 2) Changing What would you have to have to have a
changing velocity?
Either the speed
and/or direction must
change

9. Name the 3 parts on a car that control velocity

10. Review 1) What is the difference between speed and velocity?
a) none, they are the same
b) speed is 2x faster than velocity
c) speed has a direction
d) velocity has a direction

11. Velocity
Explain why we say all 3 cars are changing their velocity

12. Review Change the following speeds to velocity a) 22.7 m/s b) 45 mph
What is the formula for velocity?
v= Δx/Δt
What would -3m/12 s tell you?
You could be going opposite of positive (or the other direction from which you started)backing up

13. Explain what is happening in this picture using the words speed and velocity

14. If the slope of a displacement-time graph gives us _____
If the slope of a displacement-time graph gives us _____.(v= Δx/t) What would the slope of a velocity-time graph give us?
? = v/t
Acceleration

15. Sometimes we are interested in how fast the velocity of an object is changing
Acceleration
Unit: m/s² or m/s S
Formula: a=Δv/t
= v-v₀/t

16. Velocity-time graph (Y-axis is important!)

17. What do the following lines tell us?

18. The speed-time graph shows how the speed of a bus changes during part of a journey.

19. a) OA - the speed of the bus is changing
a) OA - the speed of the bus is changing. Therefore, according to the definition, the bus has an acceleration.
AB - the speed does not change. The bus has a constant speed of .
BC - the bus is slowing down. Its speed is changing. Therefore, according to the definition, the bus has an acceleration.
CD - The bus is stationary.
DE - the speed of the bus is changing. The bus has an acceleration.
EF - the speed does not change. The bus has a constant speed .

20. A velocity-time graph can be + or -, but so can acceleration

21. Velocity…is it changing? Yes or no?