Final answer:
The inline skater's acceleration is calculated using the change in velocity over time, which is 2 m/s².
Step-by-step explanation:
To find the acceleration of the inline skater, we can use the formula a = ∆v / ∆t, where a is acceleration, ∆v is the change in velocity, and ∆t is the change in time. The skater's change in velocity (∆v) is the final velocity minus the initial velocity, which is 9 m/s - 3 m/s = 6 m/s. The change in time (∆t) is 3 seconds. Thus, the acceleration a is 6 m/s divided by 3 s, giving us an acceleration of 2 m/s².
So, the correct answer to the question 'An inline skater goes from 3 m/s to 9 m/s in 3 seconds. What is the acceleration?' is A. 2 m/s².