Finding velocity in a velocity-time graph

Question

How do you find average velocity in a velocity time graph for kinematics?

Answer 1

To find the average velocity you need a time interval over which to measure the average velocity. Let’s say we want to measure the average velocity between time t₁ and time t₂. We read off from the graph the velocity v₁ corresponding to t₁ and v₂ corresponding to t₂. Then we add v₁+v₂ and divide the sum by 2.

EXAMPLE: Let’s imagine we want the average velocity between 2 seconds and 8 seconds where the t axis is measured in seconds. At 2 seconds let’s say from the graph that the velocity is 10 m/s and at 8 seconds it’s 20 m/s, then over the time interval 2 seconds to 8 seconds, the average velocity is (10+20)/2=15m/s.