UPSC/PCS -CSAT Formula

 Day -1 

Time, Speed and Distance

Speed=  distance/ time

Important Conversion Factors: 1km/hour=15/8 metter/second and 1 minute=18/5 km/hours 

Average Speed  =total distance travelled/total time taken =d1+d2+d3+....../t1+t2+t3+....

 the distance is constant, then average speed is given by harmonic mean of two speeds:

S avg = 2S1S2/S1+S2

If the time is constant, then average speed is given by arithmetic mean of two speeds:

Savg =S1+S2/ 2