Answer:
0.8 m/s²
Step-by-step explanation:
Convert km/h to m/s:
20 km/h × (1000 m / km) × (1 h / 3600 s) = 5.56 m/s
50 km/h × (1000 m / km) × (1 h / 3600 s) = 13.89 m/s
Acceleration is change in velocity over change in time:
a = Δv / Δt
a = (13.89 m/s − 5.56 m/s) / 10 s
a = 0.83 m/s²
Rounded to one significant figure, the car accelerates at 0.8 m/s².