Question

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

Answer 1

Let the total distance covered by bus be s km

As we know that speed=Distancetimespeed=Distancetime

Which gives, time=Distancespeedtime=Distancespeed

Time for first third is (t) = s320s320

Time for two third is (t′)=2s360(t′)=2s360

Now, we also know that

Averagespeed=TotaldistanceTotaltimeAveragespeed=TotaldistanceTotaltime

Averagespeed=st+t′Averagespeed=st+t′

Putting the values oft,t, &t′t′ from above we get

Averagespeed=ss320+2s360Averagespeed=ss320+2s360

Averagespeed=ss3×20+2s3×60Averagespeed=ss3×20+2s3×60

Averagespeed=ss3×20+2s3×60Averagespeed=ss3×20+2s3×60

Averagespeed=ss60+2s180Averagespeed=ss60+2s180

Averagespeed=s3s+2s180Averagespeed=s3s+2s180

Averagespeed=s5s180Averagespeed=s5s180

Averagespeed=s×1805s
Averagespeed=s×1805s

Average speed=36Km/h

Cheers!!!!! ☺️

Answer 2

V1 = 5.55m/s
V2 = 16.67m/s
V = 2 v1 v2 ÷ ( v1 + v2 )
V = 2 × 5.55 × 16.67 ÷ (5.55 + 16.67)
V= 185.18 ÷ 22.23
V = 8.33 m / s


Hope it helps you ...
Mark me as brainlist plzzzzzzz