q of ice and q of water

[605324529]

Why does q_ice= -q_water?
Thanks!

[Elizabeth Harty 1A]

The heat lost by the water (indicated by the negative sign) is equal to the heat gained by the ice (the positive sign).

[Minh Ngo 4G]

Because all the heat lost by water ( - sign) has to be gained by ice ( + sign). Even though it doesn't matter, it is conventional to put the negative sign on the side that lost heat, and since heat flows from hot to cold, in this case, you would put the negative sign on q water

[Betania Hernandez 2E]

The heat lost by the system is the heat gained by the surroundings. In this case, since the heat is lost by the water it is negative and the heat of the ice is positive since it gained the heat.

[Ashley Nguyen 2L]

If ice is placed in water, the system will attempt to equilibrate with heat flow from the water to the ice. Therefore, qWater = -qIce. This can also be derived from the fact that qWater + qIce = 0, since all heat is being exchanged between the 2 objects and nothing else.

[Anokhi Patel 2B]

Because in the phase change heat lost from the water must equal the negative heat gained by the ice.

[Bryce Barbee]

This is because energy has to be conserved. Therefore, if heat is loss by ice when turning to water, then that equal amount of energy must be transferred to the water.

[Jacob Villar 2C]

Due to conservation of energy, the heat lost by the water must be equal to the heat gained by the ice

[KHowe_1D]

The heat lost by the water has been gained by the ice so you have negative q_water and a positive q_ice.