Temperature is not an energy store.

Temperature describes thermal state; in an ideal gas it is proportional to mean translational kinetic energy. Internal energy includes microscopic kinetic and potential energy. Heat is energy transferred because of a temperature difference.

For a single phase with approximately constant specific heat capacity, Q = mcΔT. Conduction transfers energy through interactions, convection transports warmer fluid, and radiation transfers energy by electromagnetic waves. Temperature intervals in kelvin and degrees Celsius have the same size.

INTERACTIVE MODEL

Energy into water

Water mass / kg0.2

READ THE GRAPH

Explore the relationship

One liquid phase; c = 4180 J kg⁻¹ K⁻¹; no heat loss.

Temperature rise / K

Tap or focus a plotted point to read its values.

View plotted data as a table

Explore the relationship
Series	Energy / kJ	Temperature rise / K
Temperature rise / K	0	0
Temperature rise / K	0.333333	0.398724
Temperature rise / K	0.666667	0.797448
Temperature rise / K	1	1.19617
Temperature rise / K	1.33333	1.5949
Temperature rise / K	1.66667	1.99362
Temperature rise / K	2	2.39234
Temperature rise / K	2.33333	2.79107
Temperature rise / K	2.66667	3.18979
Temperature rise / K	3	3.58852
Temperature rise / K	3.33333	3.98724
Temperature rise / K	3.66667	4.38596
Temperature rise / K	4	4.78469
Temperature rise / K	4.33333	5.18341
Temperature rise / K	4.66667	5.58214
Temperature rise / K	5	5.98086
Temperature rise / K	5.33333	6.37959
Temperature rise / K	5.66667	6.77831
Temperature rise / K	6	7.17703
Temperature rise / K	6.33333	7.57576
Temperature rise / K	6.66667	7.97448
Temperature rise / K	7	8.37321
Temperature rise / K	7.33333	8.77193
Temperature rise / K	7.66667	9.17065
Temperature rise / K	8	9.56938
Temperature rise / K	8.33333	9.9681
Temperature rise / K	8.66667	10.3668
Temperature rise / K	9	10.7656
Temperature rise / K	9.33333	11.1643
Temperature rise / K	9.66667	11.563
Temperature rise / K	10	11.9617
Temperature rise / K	10.3333	12.3604
Temperature rise / K	10.6667	12.7592
Temperature rise / K	11	13.1579
Temperature rise / K	11.3333	13.5566
Temperature rise / K	11.6667	13.9553
Temperature rise / K	12	14.3541
Temperature rise / K	12.3333	14.7528
Temperature rise / K	12.6667	15.1515
Temperature rise / K	13	15.5502
Temperature rise / K	13.3333	15.949
Temperature rise / K	13.6667	16.3477
Temperature rise / K	14	16.7464
Temperature rise / K	14.3333	17.1451
Temperature rise / K	14.6667	17.5439
Temperature rise / K	15	17.9426
Temperature rise / K	15.3333	18.3413
Temperature rise / K	15.6667	18.74
Temperature rise / K	16	19.1388
Temperature rise / K	16.3333	19.5375
Temperature rise / K	16.6667	19.9362
Temperature rise / K	17	20.3349
Temperature rise / K	17.3333	20.7337
Temperature rise / K	17.6667	21.1324
Temperature rise / K	18	21.5311
Temperature rise / K	18.3333	21.9298
Temperature rise / K	18.6667	22.3285
Temperature rise / K	19	22.7273
Temperature rise / K	19.3333	23.126
Temperature rise / K	19.6667	23.5247
Temperature rise / K	20	23.9234

Probe along the horizontal axis0Temperature rise / K: 0

Explore: Double the mass. Compare the temperature rise for the same energy input.

Q=mc\Delta T

WORKED EXAMPLE

Heat 0.20 kg of water by 15 K; c = 4180 J kg⁻¹ $K^{-1}$ .

Q = 0.20 × 4180 × 15.
The water gains 12 540 J, assuming no phase change.

Assumed knowledge

Rearranging equations; kilograms and joules.

Learning checkpoints & source

YOUR LEARNING CHECKPOINT

Distinguish temperature, heat and internal energy.
Use specific heat capacity and temperature change.

QCAA Physics · Unit 1 · Heating processes ↗

READY TO TRY IT?

Temperature is not an energy store.

Energy into water

Explore the relationship

Heat 0.20 kg of water by 15 K; c = 4180 J kg⁻¹ K−1K^{-1}K−1.

Put the idea to work.

Heat 0.20 kg of water by 15 K; c = 4180 J kg⁻¹ $K^{-1}$ .