To determine the amount of energy required to raise the temperature of a substance, you can use the formula:
Q = m * c * ΔT
Where:
Q is the amount of energy required,
m is the mass of the substance,
c is the specific heat of the substance,
ΔT is the change in temperature.
In this case, the mass of the steel is 250 grams, the specific heat is 0.11 cal/gram oC, and the change in temperature is 40 oC - 15 oC = 25 oC.
Now we can substitute the values into the formula:
Q = 250g * 0.11 cal/g oC * 25 oC
Q = 687.5 cal
Therefore, the amount of energy required to raise the temperature of 250 grams of steel from 15 oC to 40 oC is 687.5 calories.