1. Acceleration Part 3 – World Winning Rube

2. Review In previous learning we have looked at the differences how objects can move: Speed vs. Velocity However, these don’t tell us very much. Speed is a snapshot of how fast an object is going in an instant. Velocity showed us that more likely, objects are measure over an extended period of time.

3. Average Car Travel Although speed and velocity help to describe motion, they leave out a lot of information. Think of a typical drive to school. Driveway to residential street – Residential street to stop sign – Stop sign to major street – Major street to stopping at the school -

4. ACCELERATION The change of velocity of an object over time. Think of when we learned about velocity, all we are doing is adding how much time it took to change the velocity. A vector, therefore there is direction (or + or - ) of motion and a number value. Examples... Car accelerates from 0km/h To 60 km/h in 30 seconds!

5. An object is accelerating if it is changing its velocity. Sometimes an object can be accelerating and getting faster, or an object can be decelerating and slowing down. Think of a car at a stop light: – When it sees the red light it is decelerating and when it sees the green light after being stopped it starts to accelerate.

6. http://www.physicsclassroom.com/Class/1DKi n/U1L1e.cfm

7. FORMULA FOR ACCELERATION Acceleration is measured in 2 quantities: The change of the velocity of an object in the amount of time. In order to calculate acceleration in this time, we simply take the second velocity value, subtract the first velocity value and divide by total time.

8. FORMULA FOR ACCELERATION

9. If we were to look at the velocity of an object over time, we can see that this object is constantly accelerating. The velocity in m/s increases by 10, each second of time that passes.

10. If we were to plug in the value of the first and last velocity, we well as the total time, this is the formula we would get:

11. ACCELERATION UNITS If we look at the final math for our last example, you can see that we get velocity over time. Therefore our final units are actually: – m/s/s or m/s 2 – km/h/h or km/h 2

12. Check Your Understanding To test your understanding of the concept of acceleration, consider the following charts and plug them into the acceleration formula. Use the equation for acceleration to compare the accelerating of the 2 objects.

14. Check Your Understanding Practice A: Practice B: Comparison: