The specific heat of iron is 0.11 cal (g°C). A cafeteria fork made of iron has a mass of 20 grams. How much heat energy is needed to raise the temperature of this fork from 25°C to 75°C?

The amount of energy needed is 110 calories. We know this by dong the following:

Q=20*0.11 * (75-25)

⇒Q=20*0.11*50

⇒Q=110 cal

Bu doing this you have the required heat represented as Q that is supposed to raise the temperature of fork that will be equivalent to the mass multiplied by the specific heat and also by the change in temperature