Question

Answer the following question based on the graph below.Find the average speed from t = 0 - 12 seconds.

Answer 1

ANSWER

0.917 m/s

EXPLANATION

Average velocity depends on the displacement of the object, which means that it doesn't depend on the path taken, only on the difference of initial and final position.

On the other hand, average speed depends on the distance, so this quantity depends on the path taken. The average speed is,

$s_{\text{avg}}=\frac{d}{\Delta t}$

The time taken is the same, 12 seconds. To find the distance we have to see the path of the object. First, it travels from 7m to 3m, so that is 4m. Then, between 3s and 5s it is not moving. After that, between 5s and 7s it moves from 3m to 5, so that is 2m more. For the next second, it doesn't move, and finally, between 8s and 12s, it moves from 5m to 0m, so we have another 5m. In total, the distance covered by the object is,

$d=4m+2m+5m=11m$

Thus, the average speed of this object is,

$s_{\text{avg}}=\frac{11m}{12s}\approx0.917m/s$