Question

heat and calorimetry

• specific heat capacity
• power

q→heat ←closed system
ti δt tf
q = c δt
heat capacity → c = mc
q = mc δt
c = q / (mδt) → j / (kg °c) | j / (kg k)
specific heat capacity
james prescott joule (1818 - 1889)
performed many experiments to establish the
mechanical equivalent of heat - the work needed
to produce the same effects as heat transfer.
1000 cal = 4187 j
joules experiment established the
work. as the masses descended, they caused the paddles to
do work on the water. the result was a temperature
increase, measured by the thermometer. joule found that
work was proportional to w and thus determined the mechanical
equivalent of heat.

Explanation:

Step1: Identify the problem - heat transfer

The main concept here is heat transfer in a closed - system, and the formula $\varPhi=mc\Delta T$ is used to calculate the heat transferred.

Step2: Understand the variables

$\varPhi$ is the heat energy, $m$ is the mass of the substance, $c$ is the specific heat capacity, and $\Delta T$ is the change in temperature.

Step3: Consider Joule's experiment

Joule's experiment established the mechanical equivalent of heat. He found that work done (by the descending masses) is equivalent to heat. Given $1000\ cal = 4187\ J$, it shows the conversion between calorie (a unit of heat) and joule (a unit of work/energy).

Answer:

The key concepts are heat transfer using $\varPhi = mc\Delta T$ and the mechanical equivalent of heat established by Joule's experiment.