1. Speed, Distance, Displacement and Velocity

2. Point A --------> Point B
Frame of Reference
- In order to measure the distance of an object we must use a frame of reference.
Point A > Point B
- These are usually distinct points on the Earth's surface or distinguishing points in the sky.

3. Distance is a scalar quantity and tells you only the magnitude (number sum only) of a path taken.

4. Displacement is the shortest distance between the starting point and the end point.

5. Distance vs. Displacement
You drive the path, and your odometer goes up by 8 miles (your distance).
Your displacement is the shorter directed distance from start to stop (yellow arrow).
What if you drove in a circle?
start
stop

6. Speed is the distance travelled
by a moving object over
a period of time

7. Constant speed
A moving object that doesn’t change it’s speed travels at constant speed
Constant speed means equal distances are covered in an equal amount of time

8. Calculating Speed Speed = Distance Time
If a runner travels 100 m in 10 seconds what was his average speed?
Probably not constant
Can solve for the other pieces too
Distance = speed x time
Time = Distance Speed

9. Velocity is speed in
a given direction

10. instantaneous velocity - the velocity that something has at any one instance
(The terms instantaneous speed and avg. speed may also be used)

11. The average velocity for a trip might be 53 miles/hour.
However, during this trip your instantaneous speed might have been 0 miles/hour at a stoplight or 70 miles/hour on the open road.