Question

At 18°C, a brass cube has an edge length of 27 cm. What is the increase in the cube's surface area when it is heated from 18°C to 61°C? The linear expansion coefficient of brass is 19 × 10^-6 /C°.

Answer 1

linear thermal expansion coefficient , a = 19 *10^-6 1/degree C

Now, area thermal expansion coefficient = 2a

for the increase in surface area

increase in surface area = surface area * 2a * increase in temperature

increase in surface area = 6 * 27^2 * 2 * 19 *10^-6 * (61 - 18)

increase in surface area =7.15 cm^2

the increase in surface area is 7.15 cm^2