Final answer:
To calculate the car’s average acceleration, we use the formula a = ∆v/∆t, resulting in an average acceleration of 2.77 m/s² when it accelerates from rest to 19.4 m/s in 7 seconds.
Step-by-step explanation:
The student is asking about the average acceleration of a car which accelerates from rest to 19.4 m/s in 7 seconds. To find the average acceleration, we use the formula a = ∆v/∆t, where ∆v is the change in velocity and ∆t is the change in time. Since the car starts from rest, the initial velocity (vi) is 0 m/s and the final velocity (vf) is 19.4 m/s. So, ∆v = vf - vi = 19.4 m/s - 0 m/s = 19.4 m/s. The change in time ∆t is 7 seconds.
Plugging these values into the formula gives the car’s average acceleration:
a = ∆v/∆t
= 19.4 m/s / 7 s
= 2.77 m/s²
Therefore, the car's average acceleration is 2.77 meters per second squared.