Physics · Grades 9–12
Heating versus changing state · Revision sheet
Choose between mcΔT and mL using the physical process.
Learn the idea
Temperature rise
Use Q = mcΔT when the sample's specific heat is treated as constant and no phase change occurs.
Phase change
At the phase-change temperature, use Q = mL for the mass that changes state.
Heating curve
A constant-temperature section can still involve energy transfer while a pure substance changes phase under suitable conditions.
Assumptions
Real apparatus may heat up and lose energy. A simple calculation must say when these effects are neglected.
Explain without looking
- Why can a formula choice not be made from mass alone?
- A 0.5 kg sample receives 75000 J during complete melting at constant temperature. Find latent heat.
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Independent educational review required. Grade bands are approximate; these are not officially aligned curricula.