Acar traveling with constant speed travels 150 km in 7200 s. what is the speed of the car? express the speed to two significant figures and include the appropriate units.

  The given terms here are: Distance = 150 km Time = 7200 s Speed =?   To express the speed in appropriate units, in this given we can simply kilometer to meter which is the SI unit for distance. Hence, we do the conversion first. 
1.    Conversion 150 km = m? 1 km = 1000 m   150 km x 1000 m / 1 km = 150, 000 m   
2.    To find speed, we drive the formula d = vt where v = velocity or speed to v= d/t 
V = d / t 
V = 150, 000m / 7200 s 
V = 20.83 m/s 

Hence, 20. 83 m/s is the speed.