Question

On a 60 km straight road, a bus travels the first 30 km with a uniform speed of 30 kmh-1
how fast must the bus travelthe next 30 km so as to have average speed of 40 kmh-1 for the entire trip?​

Answer 1

Answer:

I hope it's helpful

Explanation:

Given:

Total distance =60km

Average speed of entire journey=40km/h

Total Time taken =

total distance/average speed

=60/40

=3/2hr

Case :1

Let us CALCULATE time taken to cover first 30km

Speed=30km/h

Distance=30km

T=distance/ speed=30/30

=1hr -----equation ( 1)

Case: 2

Let us CALCULATE time taken to travel next 30km

Let speed be =Xkm/ h

X=30KM/t

t=30/X hours ----equation( 2)

Total time = add equation 1 and 2

=1 +30/X

Since total time =3/2 he

3/2 =1 +30/X

3/2-1 =30/X

1/2 =30/X

X=60km/h

Therefore bus should travel next 30km distance at a speed of 60 km/h