A car travelling at 15 m/s increases it's speed to 20 m/s in 10 seconds. its average acceleration is?

Ave. acceleration = change in velocity / time = (vf-vi) / t

vf = final velocity = 20m/s

vi = Initial velocity = 15m/s

t = time = 10sec.

So, the ave. acceleration is = (20 m/s - 15 m/s) / 10 sec

= 5 m/s / 10 sec

= 1/2 m/s² or 0.5 m/s²