# Heat Transfer Formula

Heat, a measure of thermal energy, can be transferred from one point to another. Heat flows from the point of higher temperature to one of lower temperature. The heat content, *Q*, of an object depends upon its specific heat, *c*, and its mass, *m*. The Heat Transfer is the measurement of the thermal energy transferred when an object having a defined specific heat and mass undergoes a defined temperature change.

Heat transfer = (mass)(specific heat)(temperature change)

*Q = mcΔT *

*Q* = heat content in Joules

*m* = mass

*c* = specific heat, J/g °C

*T* = temperature

*ΔT* = change in temperature

Heat Transfer Formula Questions:

1) How much energy is transferred if a block of copper with a mass of 50 g is heated from 20°C to 100 °C? The specific heat of copper, Cu, is c = 0.386 J/g°C.

Answer: The temperature change Δ T = 100 °C - 20 °C = 80 °C. The mass, m = 50 g. Use the formula for Heat Transfer.

Q = mcΔT

Q = (50 g)(0.386 J/g°C)(80 J/g°C)

Q = 1544 Joules

2) The specific heat for aluminum is c = 0.900 J/g°C. What mass of aluminum is required to cause a heat transfer of 1500 Joules if the temperature change is 33 °C?

Answer: The change in temperature, ΔT = 33°C, and the specific heat for aluminum, c = 0.900 J/g°C. The heat transfer Q = 1500 Joules.

Q = mcΔT

m = Q/(cΔT)

m = 1500 Joules/(0.900J/g°C)(33°C)

m = 1500 Joules/(29.7J/g)

m = 50.51 g

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