Question

a car is moving on a straight road covers one third of distance with a speed of 20 km/h and rest with a speed of 60 km/h along a straight line find the average velocity of car

Answer 1

1/3 part:-
distance=x/3 km
speed=20km/hr
therefore,time = d/s =(x/3)/20 = x/60 hr

2/3 part:-
distance = 2x/3
speed = 60km/hr
therefore,time = (2x/3)/60=x/90 hr

thus, avg velocity = (x/3 +2x/3)/(x/60 +x/90)
=. x/(3x+2x / 180)
=180x/5x
=36 km/hr