Question

A car travels from a point A to point B at constant speed of 50 km/h. On return
journey along the same path, it travels at a constant speed of 40 km/h. Find its
distance travelled, displacement and average speed.
nan​

Answer 1

let the distance between A and B be x

Speed ¹ = 50kmph

therefore time taken = x/50

return journey

speed ²=40kmph

time taken = x/40

total distance travelled =x+x=2x km

displacement =0

average speed = total distance/total time

= 2x/(x/50+x/40)

= 2x÷[ x(40+50)/200]

= 2*200/90

= 45 kmph