2. A hockey player is skating in a straight line at 1.5 m/s. He then increases his speed to 7 m/s in 3 s. What is his average acceleration during this 3 s?

To find the average acceleration of the hockey player during the 3 seconds, we can use the following formula:

average acceleration (a) = (final velocity - initial velocity) / time

In this case, the initial velocity is 1.5 m/s, the final velocity is 7 m/s, and the time is 3 seconds.

So, plugging in these values into the formula, we get:

a = (7 m/s - 1.5 m/s) / 3 s

Now, let's do the calculation:

a = (5.5 m/s) / 3 s

Dividing 5.5 m/s by 3 seconds, we get:

a ≈ 1.83 m/s²

Therefore, the average acceleration of the hockey player during the 3 seconds is approximately 1.83 m/s².