Asmall pebble is heated and placed in a calorimeter containing 25 ml of water at 25°c. the water reaches a maxiumum temperature of 26.4°c. how many joules of heat were released from the pebble?

The amount of heat released by the pebble is equal to the amount of heat absorbed by the water, which is given by

where
m is the mass of the water
is the specific heat capacity of the water
is the increase in temperature of the water.

The density of the water is , and , so the mass of the water in the problem is

so if we substitute in the formula, we get the amount of heat absorbed by the water (and released by the pebble):

This is the answer: body 1 + engine 2