Recently, I learned that specific heat capacity is not constant in different temperatures and it depends on the temperature.If I have diagram like this
(consider that the red part is a quarter of ellipse)
1-How much energy(in calories) do we need to change the temperature of 1 kilogram of metal A from 0 to 40 Celsius?
2-How can we choose a single value (as an average value) for the specific heat capacity of metal?