A rolling ball moves from x1 = 3.4cm to x2 = - 4.2cm during the time from t1 = 2.0s to t2 = 6.1s. What is its average velocity?

To find the average velocity you need to count the distance and time. In this case, the distance is x2-x1 since the ball move from x1 to x2. The calculation would be: (-4.2cm) - 3.4cm = - 7.6cm. 7.

The time would be t2-t1, then the calculation would be: 6.1s - 2s = 4.1s

Then the average velocity is - 7.6cm / 4.1s = - 1.85cm/s