Question

A car running between two points P and Q on a straight path. If it travels half of distance between
P and Q with velocity 40 km/h and other half with 60 km/h and return in the same manner. The
average speed of the car is. explain strep by step

Answer 1

Step-by-step explanation:

Avg Speed = Total distance/Total time

Let the distance between P to Q is 2S

It travels half of distance with 40km/h

= S distance with 40km/hr

Time Taken = distance/speed

= S/40 hr

and other half of distance with 60km/h

= S distance with 60/hr

Time Taken = S/60 hr

Return with same manner

= S distance with 40km/hr (=Time taken = S/40 hr)

and other half of distance with 60km/h

= S distance with 60/hr (=Time Taken = S/60 hr)

Hence, total distance of the whole journey

= 2S + 2S

= 4S

& Total time taken

= S/40 + S/60 + S/40 + S/60

= (3S+2S+3S+2S)/120 hr

= 10S/120 hr

= 1S/12 hr

Average Speed = 4S/(1S/12) km/hr

= (4S×12)/1S km/hr

= 48S/1S km/hr

= 48 km/hr