Question

A railroad track is made of individual rails of steel each 29 feet in length. By what length would one rail change from a cold winter day when the temperature is –10 degree C to a hot summer day at 30 degree C? (1 m = 3.281 ft),(1km = 1000m) (5280 ft = 1 mile) (1 mile = 1.609 km)

Answer 1

Solution-

The rails are made of the steel,

thermal expansion coefficient for steel = 13X10-6 /C

The formula for the linear thermal expedition,

L= length for each rail section = 29 ft at temperature 20 (normal)

Delta T = Total change in temperature

In summer = 30-20 = 10

in winter = -10-20= -30

(a) Change in Length in Summer

(b) Change in Length in Winter

Total variation from winter to summer,

Therefore, the total variation in length is 0.0151 ft.