The fig. shows the displacement-time graph of a particle moving on a straight line path. What is the average velocity of the particle over 10 seconds?

(1) 2 m/s             (2) 4 m/s             (3) 6 m/s             (4) 8 m/s

Dear Student

$Average Velocity\overrightarrow{ v} =\frac{Displacement}{total time}$
We need to find out the average velocity for whole time interval that is 10 s.

Particle starts from 60 m in 0 seconds and reach to 40 m in 10 seconds after covering distance 50 and 30 m in 6 seconds and 4 seconds respectively.
So net displacement is 60 -40 = 20 m
Time = 10 s
Average velocity  = 20/10 = 2 m /s.

Regards

Total time = 10 s
Hence average displacement = -  20/10 = - 2 m/s