Question

In a winter season, a heat pump is used to warm the room. A heat pump works 60 J on the pump while it absorbs 90 J of heat. How much heat is delivered to the house?

• A. 5,400 J.
• B. 150 J.
• C. 30 J.
• D. 1.5 J.
• E. 0.67 J.

Answer 1

Answer: (C)

30 J.

Since $60J$ of the $90J$ of heat are used to do work, there are only $30$ joules of heat left to deliver to the house, i.e, $90J-60J=30J$