3. Review Choose A = Speed B = Velocity Magnitude and direction Scalar Vector Magnitude only

4. What is a motion map? A motion map represents the position, velocity, and acceleration of an object at various clock readings. Represents position and velocity only. It’s like taking a snapshot photo of a moving object. Each image reveals the position of the object at one-second intervals.

7. Review

8. velocity  How fast an object changes is its velocity.  Three ways for Acceleration to occur: 1. Object Speeds up, + acceleration) 2. Object Slows down, - acceleration) 3. Object Changes direction Is the slope of a velocity vs. time graph

9. The unit for acceleration is calculated by dividing the unit for velocity (m/s) by the unit for time (s) You get m/s/s, we write m/s 2 we say meters per second squared time V f - V i

10. downward  A force that pulls us downward toward the center of the Earth. Falling objects accelerate DOWNWARD at the rate of gravity, or 9.8 m/s 2.

11.  In distance vs. time graphs, acceleration is displayed with a curve, because it is gradual. + or –acceleration? + or - acceleration D D tt

12. Practice Problems B. What is the acceleration of a bus that increases its speed by 14m/s in 4 seconds? A. If an object starts from rest and accelerates to 60 m/s in 10 seconds, what was the acceleration?

13. Practice Problems C. A biker starting from rest reaches a final speed of 3.0 m/s in 3 seconds. What is the acceleration of the biker? D. The fastest land mammal, the cheetah, can accelerate at a rate of 30 m/s/s. How fast will the cheetah be going after 2 seconds if the cheetah started from rest?

14. E. A rocket ship is traveling at 18,000 m/s when it turns on its rocket thrusters. After 50 seconds the space ship has reached a speed of 28,000 m/s. What is the ship’s acceleration? F. A roller coaster has a velocity of 40 mi/hr at the bottom of the hill. It slows to a velocity of 12 mi/hr during the 7 seconds it takes to reach the top of the next hill. What is its acceleration? Practice Problems