2. Motion Speed, Velocity, and Acceleration

3. Frames of Reference w The object or point from which movement is determined w Movement is relative to an object that appears stationary w Earth is the most common frame of reference

4. Questions w What is the frame of reference for the sunset? w What is a frame of reference? w What is the most common frame of reference?

5. Motion w Motion is a change in position relative to a frame of reference w Speed is the distance traveled in a given amount of time w Speed=distance w time

6. Speed w The units for speed: w meters/second (m/s) w kilometers/hour (km/hr) w Speed that does not change is constant speed

7. Average speed w Total distance divided by the total time w Formula: w Total distance total time

8. Velocity w Speed in a given direction w Velocities in the same direction combine by adding w Velocities in different directions combine by subtracting

9. Interesting fact  Rockets are launched in the same direction of the earth ’ s rotation to get an extra boost of 1800 km/hr to its speed

10. Questions w What is motion? w What is speed? How is it calculated? w What is average speed?

11. Questions w How is velocity different from speed?  Which two factors determine an object ’ s velocity?

12. Acceleration w The change in velocity w Acceleration is measured in m/sec/sec or m/sec 2 w Formula is: w a = (final velocity - original velocity)/time between the 2 velocities

13. Deceleration vs. Acceleration w A decrease in velocity is deceleration or negative acceleration w A distance-time graph for acceleration is always a curve

14. Questions w What is acceleration? w What is the shape of a distance-time graph for acceleration?