Question

A boy is running on a straight road.He runs 500m towards north in 2minutes 10seconds and then turns back and runs 200m in 1.00 minute.Calculate s average speed and magnitude of average velocity during first 2minutes 10seconds and s average speed and magnitude of average velocity during the whole journey.

Answer 1

Let the boy start from a point A and B point is 500 m away from it . And a C point which is 200 m away from point B . 
Now Time taken to reach at point B. T= 130s Distance = 500m avg speed = 500/ 130 = 3.7m/s 
displacement = 500m v.avg = 500 / 130 = 50 / 13 = 3.7 m/s 
Total joutney's avg speed= (500/ 130 + 200 / 60 ) / 2= ( 3.7 + 3.3 ) / 2 = 7 / 2 = 3. 5 m/s 
as we know the AC = 300m And time taken from reaching A to C is = 130 - 60 sec = 70 sec 
Total avg velocity = 300 / 70 = 4.2 m/s 
May it helps you :) 

Answer 2

Explanation:

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