1. Ch. 11 Sec. 3
Acceleration

2. Acceleration Rate of change in velocity.
Really a description of “how fast you can go in a certain amount of time”.
Good acceleration is being “quick to change”.

3. Change in Speed Acc. = final velocity – original velocity time
Push or pull feeling
Acceleration by increasing speed or decreasing in speed (negative acceleration)
Acc. = final velocity – original velocity time
Units: m/sec/sec

4. Change in Direction
Turning a curve changes acceleration even at constant speed
Constant Acceleration
Steady change in velocity in a straight line

5. Acceleration Problem
A car increases its speed from 60 km/hr to 80 km/hr in 4 seconds. What is the car’s acceleration?
Acc = Δ velocity
time
80 km/hr – 60 km/hr
4 sec.
5 km/hr/sec.
1st second – 65 km/hr
2nd second – 70 km/hr
3rd second – 75 km/hr
4th second – 80 km/hr

6. Acceleration problem
An airplane reduces its speed from 250 km/hr to 175 km/hr in order to come into the run way. What was the negative acceleration of the plane?

7. Speed-Time Graph
Slope of the speed time graph is acceleration

8. Distance-Time Graph Nonlinear graph showing accelerated motion
Curve motion

9. Instantaneous Acceleration
How fast velocity is changing at a specific instant
Involve change in velocity or direction
Always changing

10. Acceleration problem
A runners acceleration is 5.5 m/s/s. If the runner first starts at 0.0 m/s and has a final velocity of 21.0 m/s. How long will it take?

11. Rates of Motion Table Rates Definition Equation Unit Graph Speed
Velocity
Acceleration