Question

The distance between two points A and B is 625km. Find the total space that must be left between iron rails to allow for the change of temperature from 360F in winter to 117F in summer.

Answer 1

Answer:

Given that the distance between the two places is 200 km.

Thus, the maximum length of rails is 200 km.

Let the initial length of rails be l.

Change in temperature is ΔT=(117−36)

∘

F=(117−36)×

9

5∘

C=45∘ C

Thus, the final length of rails is l

f =l(1+αΔT)=(1+2.5×10

−5

×45)l=1.001125l

But, l

f

=200 km

∴ 200 km=1.001125l

⇒l=

1.001125

200 =199.77 km

Thus, the amount of gap in rails is 200−199.77=0.23 km

Answer 2

Answer:

Given that the distance between the two places is 200 km. Thus, the maximum length of rails is 200 km.