# Latent Heat

## Homework Statement

What is the energy released as water changes temperature from 20C to -10C?

mct+lfm+mct

## The Attempt at a Solution

My physics exam is day after tomorrow, however, I have no clue about this question. I was away for a week during these lessons. Can someone please walk me through the question so I can understand.

Thank you very much.

## Answers and Replies

rock.freak667
Homework Helper
Assuming no heat losses. All the energy released goes into reducing the temperature from 20C to 0C and changing the water's phase and then lowering the temperature of the ice from 0C to -10C

Well yes, but how would I set up the equation?

rock.freak667
Homework Helper
$$Energy=m_w c_w \Delta \theta_w + m_w l_f +m_ic_i \Delta \theta_i$$

i=ice,w=water.

Can you please plug in the digits? I am confused about the temperatures.

rock.freak667
Homework Helper
$$Energy=m_w c_w \Delta \theta_w + m_w l_f +m_ic_i \Delta \theta_i$$

i=ice,w=water.

for the change in temperature of the water it is (20-0)C and for ice it is (0-(-10))=10C.