Question

A distance-time graph indicates that an object travels 2 m in 2 s and then travels another 80 m during the next 40 s. What is the average speed of the object?

Answer 1

The average speed of the object is given by the ratio between the total distance covered and the total time needed for the motion:
$v= \frac{S}{t}$

The total distance covered is:
$S=2m + 80 m = 82 m$
while the total time of the motion is
$t=2s+40 s=42 s$

Therefore, the average speed of the object is
$v= \frac{S}{t}= \frac{82 m}{42 m}=1.95 m/s$