Question

A car travels a distance of 100 kilometer it was first 50 km at a speed of 20 km per hour next 70 km per hour at a speed of 30km\h at remaining speed of 25 km\h calculate the average speed of a car

Answer 1

Answer:45km/hr

Explanation:

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Calculating Average Speed

Average speed = Total distance/elapsed time

First case

Dist.   =100km

Speed=50km/h

therefore Time=dist./speed

= 100/50= 2hrs.

Second case

Dist.   =400km

Speed=40km/h

therefore time taken= 400/40

= 10hrs

Therefore average Speed= 400+100/10+2

=500/12

= 41.67km/hr

Calculating Average Velocity

Average velocity= initial speed(u) + final speed(v)/2

Initial speed=50km/hr

Final speed=40km/hr

Average Velocity= 50+40/2

= 45km/hr