A student is investigating the specific heat capacity of a block of iron. Their method is to heat up the insulated block of iron using an electric heater and measure its temperature using a digital thermometer at regular intervals. The block will be heated up from room temperature to 80
°C. What is the independent variable in this experiment?
• The increase in temperature of the block of iron
• The mass of the block of iron
The time the block of iron takes to reach 80 °C
The energy supplied to the block of iron by the electric heater