Note that
1 km/h = (1000 m)/(3600 s) = 0.27778 m/s
Initial velocity, v₁ = 25 km/h = 6.9444 m/s
Final velocity, v₂ = 65 km/h = 18.0556 m/s
Time interval, dt = 6 s.
Calculate average acceleration.
a = (v₂ - v₁)/dt
= (18.0556 - 6.9444 m/s)/(6 s)
= 1.852 m/s²
Answer:
The average acceleration is 1.85 m/s² (nearest hundredth)