Question

A MAN TRAVELS ONE THIRD LENGTH OF A STRAIGHT ROAD WITH A CONSTANT SPEED OF 40M/S .AND THE REMAINING PORTION OF THE ROAD WITH A CONSTANT SPEED OF 60M/S.THEN CALCULATE ITS AVERAGE SPEED.

Answer 1

Let total distance = x
s1= 40m/s. D1= x/3. t1=
$\frac{x}{3 \times 40}$
S2 = 60m/s. D2= 2x/3. t2=
$\frac{2x}{3 \times 60}$
$average \: speed = total \: distance \: travelled \div total \: time$
avg. speed= x/3x+4x/360
avg. speed = 360/7= 51.4