# Question #9c5cf

May 5, 2017

If it is able to extract at least $2 J$ from the water....

#### Explanation:

If I remember correctly the Heat Pump is like a fridge where instead of using...the food compartment you take advantage of the heat produces in the grid behind it to heat up the room.
Schematically:

You can supply heat ${Q}_{h} = 3 J$ having used/extracted:
${Q}_{c} + W = 3 J$