Question

On a 60 km straight road, a bus travels the first 30 kmh^-1. How fast the bus must travel the
next 30 km so as to have average speed of 40 kmh^-1. for the entire trip​

Answer 1

Answer:

60 km/h

Explanation:

Avg speed of entire trip - V and total distance d=60Km and total time taken is t.

Avg speed in first 30Km _ v1=30Kmh-1 and time taken to cover it is t1.

Avg speed in last 30Km _ v2=? and time taken to cover it is t2.

V = d/t

V = 60/(t1+t2)

V = 60/[(30/v1)+(30/v2)]

40 = 60/[(30/30)+(30/v2)]

(30/30)+(30/v2) = 60/40 = 1.5

1 + (30/v2) = 1.5

30/v2 =0.5

v2 = 30/0.5

v2 = 60 Kmh-1