Question

A person starts to run around a square track with sides of 50 m starting in the bottom right corner and running counter-clockwise. Running at an average speed of 5 m/s, the jogger runs for 55.89 seconds. What is the difference between the magnitude of the person's average velocity and average speed in m/s? (average speed - |vav|)

Answer 1

Average velocity in any single lap is zero as he is running in opposite direction in the opposite arm of the square.

Now he ran for 55.89 s so the distance covered by him during this time,

So number of sides covered,

so in the first 4 side that is one complete lap its average velocity is zero. So the remaining 1.589 it will move 50 m in y direction and then 50*0.589=29.45 m in negative x direction. So the displacement in 55.89 s is

So its average velocity,

So the difference =5-1.03=3.97 m/s