2. Notes on Motion IV Acceleration a

3. What do you think of when someone says acceleration? It turns out that an object is accelerating if it ____________ ______________ _________________

4. Defining Acceleration Acceleration is defined as __________________________ Another way to say this is that acceleration measures how _________________________________________________ Accelerations can be ________ or ___________ But Positive acceleration _______________________ an object is speeding up. Negative acceleration _________________________ an object is slowing down.

5. Speeding Up or Slowing Down For linear motion (straight-line). Whether or not an object speeds up or slows down is determined by the direction of the acceleration COMPARED to the direction of motion (velocity). In general, if the acceleration and velocity have the _____________________________________________ then the object: ____________ _ In general, if the acceleration and velocity have _________________________________________________ ______then the object: _______________

6. Units for Acceleration English System __________________________________ Metric System ______________________________________ ________________________________________ In science the most common unit is: ________________

7. Meaning of Acceleration A car starts from rest and accelerates at 4 km/hr/s. What does this mean? This means the car ’ s velocity changes by ___________________. Starting Velocity: Velocity after 1-s: Velocity after 2-s: Velocity after 10-s: ____________ _____________

8. Meaning of Acceleration A car traveling at 10 km/hr accelerates at 4 km/hr/s. What does this mean? This means the car ’ s velocity changes by ___________________ Starting Velocity: Velocity after 1-s: Velocity after 2-s: Velocity after 10-s: __________ ___________

9. Meaning of Acceleration A car traveling at 8 km/hr accelerates at-4 km/hr/s. What does this mean? This means the car ’ s velocity changes by _____________________ Starting Velocity: Velocity after 1-s: Velocity after 2-s: Velocity after 10-s: _________ __________ _____________ __ ____________

10. Solving Problems with Acceleration Acceleration is defined as the rate of change of velocity. Since this is a rate of change we can also say that acceleration is the change in velocity over time. As an equation this looks like: v f is the __________ (ending) and v i is the _____________ (starting). This will find the average acceleration if the change in velocity is over a ___________. This will find the uniform acceleration if the acceleration is _______.

11. Solving Problems with Acceleration If we place his formula into our triangle, we can find other useful formulas from this

12. Solving Problems with Velocity and Speed If you need to find t, cover t. Since v f - v i is on top of a, _______ them.

13. Solving Problems with Velocity and Speed If you need to find v f, cover v f -v i. Since a is next to t, ________ them. Finally ______ v i to both sides.