This question is "Which procedure would best increase the amount of heat energy that is actually gained by calorimeter B? (1)increasing the length of the metal bar connecting the two calorimeters (2) increasing the thickness of the same metal bar
(3) circulating air over the metal bar
(4) placing insulation around the metal bar".
This question is from a book, and I just added some words in the answer choices to make things clearer. Please explain why you got the answer that you did.