1. Acceleration Physics 11

2. Acceleration Acceleration is a vector quantity and the direction of both the velocity and acceleration is crucial to understanding the situation Positive velocity with positive acceleration (faster to the right/up) Positive velocity with negative acceleration (slower to the right/up) Negative velocity with positive acceleration (slower to the left/down) Negative velocity with negative acceleration (faster to the left/down)

3. Velocity Time Graph From your instantaneous velocity calculations (object dropped from a cliff) plot a velocity time graph Connect the data with a line or curve of best fit If it is a linear relationship, determine the equation of the line

4. Acceleration Similar to how velocity is the rate of change of position and is determined by the slope of a line on a position time graph, acceleration is the rate of change of velocity and is the slope of a line on a velocity time graph Therefore, a position time, velocity time and acceleration time graph for a given situation are linked together

5. From Position-Time to Velocity-Time to Acceleration-Time We have seen that we can use slopes (whether from constant or instantaneous velocity) from a position-time graph to find information to draw a velocity-time graph Further, we have seen that using slopes from a velocity-time graph will provide information to draw an acceleration-time graph

6. From Acceleration-Time to Position- Time A car accelerates at a constant.75m/s 2 ; plot an acceleration-time graph to represent this situation (showing time to 10 seconds) On the graph, calculate the area under the curve for the following times: 0s-2.5s 0s-5s 0s-7.5s 0-s-10s What are the units of the area? What does this mean?

7. From Acceleration-Time to Position- Time Use the velocity data from the previous question (area under the curve) to plot a velocity time graph. From the velocity time graph, calculate the area under the curve for the following time intervals: 0s-2.5s 0s-5s 0s-7.5s 0s-10s What are the units of the area? What does this mean?

8. From Acceleration-Time to Position- Time Use the displacement information from the previous question (area under the curve) plot a displacement–time graph

9. Acceleration-Time Graph

10. Velocity-Time Graph

11. Position-Time Graph

12. Equations of Motion

13. Practice A ball is dropped from the top of a 3.5m tall building. How long does it take to hit the ground and how fast is it going when it hits the ground?

14. Practice A car can accelerate from rest to 110km/h in 7.3s; what is the acceleration and how far does it travel in this time?

15. Practice It is reasonable to have an acceleration due to braking that is 1.5x the acceleration due to gravity. If you are going 100.km/h, what is your minimum stopping distance?

16. Practice A ball is thrown up from a height of 1.5m above the ground with an initial velocity of 21m/s. How high will the object go, how long is it in the air and what is the velocity as it hits the ground?

17. Two Objects Lois Lane has fallen from the top of the Empire State Building (381m) and Superman is 4.0km away at the moment she begins falling. How fast must he fly (assume constant velocity) in order to catch her just before she hits the ground?