Velocity Pages

Overview What is velocity, and the various types What is the difference between average velocity and instantaneous velocity How to do you calculate average velocity?

Velocity Velocity describes the displacement of an object during a specific time interval. Velocity is a vector quantity, so we give: A magnitude and unit The direction Symbols: Velocity = v Example: 64 km/h north

Constant Velocity Constant velocity is when an object travels at the same speed (and direction) for each time interval. Objects that move in a straight line on a flat surface at a constant speed have constant velocity. Example: A train moving along the tracks Think uniform motion

Changing Velocity Changing velocity is when an object’s speed or direction (or both) change for each time interval. Example: A car moving in traffic;, the first minute it moves 10m, the second minute it moves 20m. What if the speed doesn’t change, but the direction does (e.g. car turning a corner)? Is that a change in velocity?

Instantaneous Velocity The velocity (both magnitude and direction) at a specific instant of time. When there is constant velocity, the instantaneous velocity is equal to the average velocity at a specific interval of time.

Average Velocity The displacement of an object divided by the time interval it takes to travel the displacement.

Example 1 A runner starts his jog 2m North of his house. The end of his run lands him 24m North of his house after 30 minutes. What is his velocity? (Remember to always write the correct formula and show your units!)

Example 2: Using Position-Time Graphs Position (m) Time (s) What is the average velocity of line A?