Final answer:
The average acceleration of a car that speeds up from 5.0 m/s to 20.0 m/s in 5.0 seconds can be calculated using the formula for acceleration, resulting in an average acceleration of 3.0 m/s², which is option C.
Step-by-step explanation:
The student is asking about calculating the average acceleration of a car that changes its speed from an initial speed to a final speed over a certain period of time. To find the average acceleration, we use the formula a = ∆v / ∆t, where ∆v is the change in velocity (final velocity minus initial velocity) and ∆t is the change in time. In this case, the car accelerates from 5.0 m/s to 20.0 m/s over 5.0 seconds.
The change in velocity is ∆v = 20.0 m/s - 5.0 m/s = 15.0 m/s. The time interval is ∆t = 5.0 s. Therefore, the average acceleration is a = ∆v / ∆t = 15.0 m/s ÷ 5.0 s = 3.0 m/s². Thus, the correct answer is C) 3.0 m/s².