1. Chapter 2: Motion

2.  Compare your maximum speed with that of a cheetah, horse, elephant, and snake. Could you win a race against any of them?

3.  Distinguish between distance and displacement.  Explain the difference between speed and velocity.  Interpret motion graphs.

5.  A reference point is needed to determine the position of an object.  Motion occurs when an object changes position relative to its reference point.

6.  Distance: how far an object has moved  Displacement: the distance and direction of an object’s change in position from the starting point  The SI unit for distance and displacement is the meter (m).

7. A runner runs from the start line 50 m north plus 30 m in the opposite direction. What is the distance? What is the displacement?

8. 40 meters 22 meters

9.  Speed: the distance an object travels per unit of time

10.  Speed = distance / time  Speed = d/t  Distance measured in meters (m)  Time measured in seconds (s)  Speed measured in meters/seconds (m/s) or kilometers/hour (km/h)

11.  Speed = d/t  Distance =  Time =

12.  A car traveling at a constant speed covers a distance of 750 m in 25 s. What is the car’s speed?

13.  A man runs at a speed of 2.30 m/s. How long does it take for the man to run 50 m?

14.  A car is travelling at 30 km/hr for 125 s. How far does the car travel in meters?

16.  Average speed: total distance traveled divided by the total time of travel  Instantaneous speed: speed at a given point in time

17. 40 meters 22 meters 4 s 11 s 10 s 2 s

18.  Motion can be shown on a distance vs. time graph  Time on x-axis  Distance on y-axis

19.  On a distance vs. time graph the slope describes the speed  Steeper slope = faster speed  Horizontal line = zero speed = object at rest

20. Distance (m) Time (s)

21.  Velocity: includes the speed of an object and the direction of its motion  Because velocity depends on direction as well as speed, the velocity of an object can change even when its speed does not!

22. Car is driving 30 km/hr, but its velocity is constantly changing!

23. 40 meters 22 meters 4 s 11 s 10 s 2 s

24.  Miss Marnik walked a distance of 1.60 km in 30 min. Find her average speed in m/s.