Final answer:
To calculate the heat absorbed by a 300-g sample of iron when heated from 30°C to 50°C, we use the formula q = mcΔT with a specific heat capacity of 0.45 J/g°C. The heat absorbed is found to be 2700 joules.
Step-by-step explanation:
The question asks about the amount of heat absorbed when a 300-g sample of iron is heated from 30°C to 50°C. To calculate this, we use the formula q = mcΔT, where q is the heat absorbed, m is the mass of the substance, c is the specific heat capacity, and ΔT is the change in temperature.
Given that the specific heat capacity of iron is 0.45 J/g°C, the mass of the iron is 300 g, and the change in temperature (ΔT) is 50°C - 30°C = 20°C, we can calculate the heat absorbed.
Using the formula, we get:
q = (300 g) * (0.45 J/g°C) * (20°C) = 2700 J
Therefore, the iron absorbed 2700 joules of heat.