I want to test how heat effects water. I place a sauce pan on the stove and turn the heat to high on the burner and observe. Which variable is the constant/control variable?

answers: to make sure that all of the broken pieces of tablet were added to the water, to allow for fair comparison of all three trials, with different particle sizes to avoid experimental error

while cooking a piece of 1/2 pound beef steak, a cast iron pan (2.4kg in weight) was heated 260 celsius.