(e) (i) Define linear expansivity of thermal expansion. (1 mark) (ii) A steel wire whose length L is 130 cm is heated to an average 180^circ C .What is the amount the wire shrinks if it is freely allowed to cool to 20^circ C (3 marks)

(i) Linear expansivity of thermal expansion refers to the fractional change in length of a material per unit change in temperature. It is a measure of how much a material expands or contracts per degree change in temperature.(ii) To find the amount the wire shrinks when it cools from to , we can use the formula for linear expansion: where:- is the change in length,- is the original length,- is the linear expansivity of the material, and- is the change in temperature.Given:- cm,- for steel is approximately , and- .Substituting the values into the formula: cmTherefore, the wire will shrink by approximately 0.0252 cm when it cools from to .