1. Acceleration Section 5.3
Physics

2. Objectives
Determine from the curves on a velocity-time graph both the constant and instantaneous acceleration.
Determine the sign of acceleration using a v-t graph and a motion diagram.
Calculate the velocity and the displacement of an object undergoing constant acceleration.

3. Units of Acceleration What are the units of acceleration? m/s²
What is a m/s²?
This can also be written as an increase of 9.8 m/s in each second.

4. What can you gain from the slope of the lines?

5. Acceleration
Acceleration can be gained from the slope of the lines on a velocity-time graph.
Since average acceleration = Δv/Δt, the v-t graph allows you to calculate the acceleration of an object.

6. Average Acceleration
Average Acceleration = Rise/Run

7. Constant Acceleration
Both Lines have a constant acceleration: 0m/s² and 4m/s²

8. Instantaneous Acceleration
What if the slope of the v-t graph isn’t constant?
Instantaneous Acceleration can be found by drawing a tangent line to the curve on the velocity-time graph.

9. Instantaneous Acceleration
Tangent Line
Then, find the slope of the tangent line to find the instantaneous acceleration.

10. Positive and Negative Acceleration
So far we have only examined positive acceleration.
We will now look at negative acceleration.
Negative acceleration depends on how you define your coordinate system.

11. Positive and Negative Acceleration
v (m/s)
v (m/s)
t (s)
t (s)
A basketball rolls up a slanted driveway. It rolls up, comes to a stop,
and then rolls back down.

12. Practice Problems
Pg 97
17-22

13. Calculating Velocity from Acceleration
If the equation: a = Δv / Δt is rearranged at the point where ti = 0, then velocity with constant acceleration can be found.
v = v0 + at

14. Practice Problems
Pg 98
23-26

15. Finding Displacement with Constant Acceleration
Final Position with Constant Acceleration:
d = d0 + v0t + ½at²
Final Velocity with Constant Acceleration:
v² = v0² + 2a(d-d0)

16. Practice Problems
Pg 103
27-30

17. Assingment
Do 5.3 Worksheet for tomorrow.