Quantity of heat, heat capacity Presentation

Thermal Conduction

Convection

Ways to change
internal body energy

Radiation

Accomplishment
mechanical work

Heat transfer

Thermal conduction

Convection

Способы изменения
внутренней энергии тела

Radiation

Mechanical Work Done

Теплопередача

With heat transfer
ΔU = Q – quantity of heat

ΔU – change in
internal energy of the body

Q – quantity of heat -
energy that the body gains or loses in heat transfer

[Q] = [J]

What does it depend on:
quantity of heat Q ?

Experiment

The amount of heat Q depends :
By mass of substance m,
From temperature changes Δt
From the kind of substance

The amount of heat that is needed in order to change body temperature by weight
1 kg of 10С, called the specific heat of matter с

In order to calculate the amount of heat needed to heat the body or emitted when it is cooled, the specific heat capacity of the substance must be multiplied by the body weight and the temperature difference.

Q = c m (t2-t1)
Q – quantity of heat;
с – specific heat of matter;
m – mass of the body;
t1 – initial and t2 – final body temperature.

Specific heat of matter с:
unit of measurement
[ с ] = [ J / kg ∙ OС]
2. It shows how much heat is needed to heat a substance with mass 1 kg of 1 0С
3. For a given substance, c is a constant value.
4. Different substances have different specific heat

Specific heat of water

What is the connection between calorie and joule?

Calorie is the amount of heat that is needed to heat 1 g of water per degree.

1 cal = 4.19 = 4.2 J
1 kcal = 1000 cal
1 kcal = 4190 J = 4200 J