Question

A car travels 30km at a uniform speed of 40km/hr and next 30km at a uniform speed of 20km/hr. Find its average speed.

Answer 1

average speed =  total distance/timetaken

so average speed = 60km/2hr
average speed= 30km/hr


answer=30km/hr

Answer 2

Hello Mate!

Speed = Distance / Time
40 = 30/ t
t= 30/40 = 3/4 or 0.75 h

20 = 30/ t
t = 30/20 = 3/2 or 1.5 hr

We know that average speed formula i.e.,

Average speed = Total Distance / Total Time

= ( 30 km + 30 km ) / ( 1.5 h + 0.75 h )
= 60 km / 2.25
= 26.7 km/h or 26.7 × 5/18 m/s = 7.4 m/s

Hope it helps☺!✌