Answer:
20,000 Joules of energy
Step-by-step explanation:
The amount of energy required to heat the metal block can be calculated using the formula:
Q = m * c * ΔT
Where:
Q = amount of energy (in Joules)
m = mass of the metal block (in kilograms)
c = specific heat capacity of the metal block (in Joules/kg degrees Celsius)
ΔT = change in temperature (in degrees Celsius)
Substituting the given values, we get:
Q = 0.5 kg * 800 J/kg°C * (100°C - 20°C)
Q = 0.5 kg * 800 J/kg°C * 80°C
Q = 20,000 Joules
Therefore, 20,000 Joules of energy was required to heat the metal block from 20 to 100 degrees Celsius.