Question

What is the average acceleration of a jet ski that goes from rest to 10 m/s west in 4 s? Take the direction west to be positive, and east to be negative.

Answer 1

The answer is 2.5 m/s^2. I hope this helps

Answer 2

From the question we come to know several important information's and based on them we can reach the desired result.
Initial speed = 0 m/s
Final speed = 10 m/s
Initial time = 0 sec
Final time = 4 sec
Then
Average acceleration = (Final speed - Initial speed)/(Final time - Initial time)
                                   = (10 - 0)/(4 - 0)
                                   = 10/4
                                   = 2.5 m/s^2
So the average acceleration is 2.5 m/s^2. I hope this has made it clear to you about the procedure of solving such problems.