1. Motion

2. Speed and Velocity An object is moving if its position changes against some background that stays the same ◦Reference frame

3. Speed and Velocity Speed describes how fast an object moves How do we determine speed?

4. Speed and Velocity To find speed, you must measure two quantities: distance traveled and the time it takes to travel that distance

5. Speed and Velocity When an object covers equal distances in equal amounts of time, it is moving at a constant speed

6. Speed and Velocity The relationship between speed, distance, and time can be investigated by plotting a distance-time graph

7. Speed and Velocity Most objects do not move at constant speed Average speed is the distance covered divided by the time it takes to travel that distance

8. Speed and Velocity Velocity describes both speed and direction

9. Speed and Velocity 1. 110m/72s=1.5 m/s toward shore

10. Speed and Velocity 1. 110m/72s=1.5 m/s toward shore 2. 38m/1.7s= 22m/s toward first base

11. Speed and Velocity 1. 110m/72s=1.5 m/s toward shore 2. 38m/1.7s= 22m/s toward first base 3. D=vt (12km/h)(5h)=60km(1000m/km)= 6x10 4 m

12. Speed and Velocity 1. 110m/72s=1.5 m/s toward shore 2. 38m/1.7s= 22m/s toward first base 3. D=vt (12km/h)(5h)=60km(1000m/km)= 6x10 4 m 4. T=d/v (2.6km)(1000m/km)/(28m/s)=93s

13. Speed and Velocity The velocity of an object changes if its speed or direction changes or both change

14. Momentum An object with more momentum would be more difficult to stop ◦Depends on both its velocity and its mass

15. Momentum For an object moving in a straight line: ◦Momentum= mass x velocity  P=mv

16. Momentum Momentum, like velocity, has direction ◦Momentum has same direction as velocity If an object is not moving, its momentum is zero

17. Momentum 1.a. (75kg)(16m/s)=1200kg m/s forward

18. Momentum b. (135kg)(16.2m/s)=2190kg m/s north

19. Momentum 1.a. (75kg)(16m/s)=1200kg m/s forward b. (135kg)(16.2m/s)=2190kg m/s north c. (5kg)72m/s)=360kg m/s eastward

20. Momentum 1.a. (75kg)(16m/s)=1200kg m/s forward b. (135kg)(16.2m/s)=2190kg m/s north c. (5kg)72m/s)=360kg m/s eastward d. (.8kg)(6.5m/s)=5kg m/s to the left

21. Momentum 1.a. (75kg)(16m/s)=1200kg m/s forward b. (135kg)(16.2m/s)=2190kg m/s north c. (5kg)72m/s)=360kg m/s eastward d. (.8kg)(6.5m/s)=5kg m/s to the left e. (48.5kg)(0m/s)=0kg m/s

22. Momentum The total amount of momentum in a system is conserved