The acceleration of the object is simply calculated by the change in the object velocity final - initial and then divided by the amount of time.
A = v/t = 72 - 54/10 = 18 km/hr
Assuming 10 seconds
18 km/3600 seconds = 0.005 km/sec
0.005 • 1000 = 5m/sec
A = v/t = 5 m/s / 10 s = 0.5 m/s.