I think I understand the idea of latent heat, but the wording (or lack thereof) of practice problems instantly makes me think that more information should be given. Either that, or I'm not understanding it correctly.
Textbooks often will ask a question like "A 100 watt heater is used to melt ice. After 60 seconds, 0.02 kg of ice has melted. Find the latent heat of fusion for ice."
When I imagine ice, I imagine something that is below zero degrees Celsius. Look at this nice graph that I made showing the temperature change of a material (H2O, for example) over time:
I want to understand that latent heat of fusion is the energy required to get from point B to point C on my graph. Is that correct?
The wording of most questions/explanations I see make me think that it is the energy required to get from point A (an arbitrary point below the melting point) to point C. For example, in the practice problem I provided earlier, it doesn't mention the original starting temperature of the ice.
In order to do experiments like this to determine the latent heat of fusion for a material (ice, for example), shouldn't the ice be just a tiny fraction of a degree off of the melting point? Or, ideally, just at the melting point?