Physic Labs

Thermal physics

Heat and specific heat capacity

Heat a mass of water at constant power and verify the calorimetry law Q=mcΔTQ=mc\Delta T by measuring how the warming slope depends on mass, heating power and specific heat capacity.

Middle school

Equipment

  • Virtual water container with heater (constant power input)
  • Sliders “Khối lượng” (mass), “Công suất” (power), “Nhiệt dung riêng” (specific heat)
  • Temperature-versus-time graph
  • “Đặt lại thời gian” (reset time) button

Procedure

  1. Measure the warming slope

    Run the heater with default mass, power and specific heat, then read the slope of the temperature–time graph. With constant power P the temperature rises linearly, ΔT/Δt=P/(mc)\Delta T/\Delta t=P/(mc); compute the expected slope and compare.

  2. Change the mass

    Press “Đặt lại thời gian”, double the mass slider and rerun: the slope halves, since twice the water needs twice the energy per degree. Record the two slopes and check their ratio matches Q=mcΔTQ=mc\Delta T.

  3. Vary power and material

    Reset and double the heating power: the slope doubles. Then lower the specific-heat slider as if heating oil or metal instead of water, and predict — then check — how the curve responds. Summarize which of m, P, c speeds or slows the warming.

Simulation

Experiment history

Calorimetry began with Joseph Black, who around 1760 distinguished heat from temperature and measured “capacity for heat” of different substances, discovering latent heat along the way. His student-era work in Glasgow launched quantitative thermal science, later refined by Lavoisier and Laplace's ice calorimeter (1780s). James Prescott Joule tied heat to mechanics: his paddle-wheel experiments of the 1840s showed that a fixed amount of mechanical work always produces the same temperature rise, fixing the mechanical equivalent of heat at about 4.2 J/cal. That equivalence turned Q=mcΔTQ=mc\Delta T from a recipe into an energy-conservation statement.

Related physicists

James Prescott JouleWilliam Thomson (Lord Kelvin)Rudolf Clausius

Related library topics

Heat and specific heat capacity