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**1. Homework Statement**

A circular metal plate of diameter

*D*needs

*Q*Joule of heat to expand and the temperature changes from 40

^{o}C to 58

^{o}C. What is the thermal energy needed to expand identical metal plate having twice the diameter for same increase in temperature?

**2. Homework Equations**

Q = mcΔT

**3. The Attempt at a Solution**

ΔT and c will be constant, but I am not sure about the mass. Should I assume the shape of the circular metal plate is cylinder and the height is constant during heating? So twice diameter means the area becomes 4 times and volume becomes 4 times? Then assuming density is constant, the answer is 4Q?

Thanks