A car is travelling at 50km/h. After 12 seconds, it is now travelling at 60km/h. What is the car's acceleration

Acceleration = (change in speed) / (time for the change)

Change in speed = (ending speed) - (starting speed)

Change in speed = (60 km/hr) - (50 km/hr) = 10 km/hr

Time for the change = 12 sec

Acceleration = (10 km/hr) / (12 sec)

Acceleration = 0.8333 km/hr-sec

Convert to a unit that we can understand:

Acceleration = (0.8333 km/hr-sec) x (1000 m/km) x (hr/3600sec)

Acceleration = (833.3 / 3600) (m-hr / hr-sec²)

Acceleration = (833.3 / 3600) (m/s²)

Acceleration = 0.231 m/s² or 0.833 km/hr-sec²