Skip navigation

ACTIVITY 1

Reading Activity

APPLICATIONS OF EXPANSION AND CONTRACTION IN SOLIDS
1. RAILWAY LINES
Gaps are left between the rails. Expansion for the rail is provided by overlapping the plane ends using overlapping joints.

If these gaps for the expansion are not provided then during hot weather, they rails may buckle out, bend and cause derailment of the train leading to destruction and accidents.
2. STEAM PIPES
Pipes carrying steam from boilers are fitted with loops or expansion joints to allow pipes to expand and contract easily when steam passes through and when it cools down.

  1. ELECTRICAL  WIRES

    They are loosely fixed to allow for contraction and expansion. During cold weather, they contract and when it is warm they expand.
    Telephone or electricity wires appear to be shorter and taut in the morning.
    However in hot afternoons, the wires appear longer and slackened.
    4. STEEL BRIDGES
    In bridges made of steel girders, one end is fixed and the other end placed on rollers to allow for expansion as shown.
  2. RIVETS
    Thick metal plates, sheets and girders in ships are joined together by means of rivets.
    The rivet is fitted when hot and then hammered flat. On cooling, it contracts, pulling the two firmly together.


6. ELECTRIC THERMOSTAT
A thermostat is used to maintain a steady temperature in some devices such as electric iron box, refrigerators, fire alarm and flashing unit for indicator lamp in motor cars.

Identifying other an area where thermal expansion is applied.

Take 5 minutes to write your response on the exercises before clicking on the feedback.