Temperature and Heat Transfer

The SI unit of temperature is Kelvin, denoted by K. It is based on absolute zero, which is the lowest possible temperature.

The relationship between Celsius and Kelvin temperature scales is K = °C + 273.15. This means that to convert a temperature from Celsius to Kelvin, you add 273.15 to the Celsius value.

The relationship between Fahrenheit and Kelvin temperature scales is K = (°F + 459.67) * 5/9. This means that to convert a temperature from Fahrenheit to Kelvin, you add 459.67 to the Fahrenheit value and then multiply by 5/9.

Heat is a form of energy that can be transferred from one object to another, while temperature is a measure of the average kinetic energy of particles in an object. Heat can cause a change in temperature, but temperature itself is not a form of energy.

The three main modes of heat transfer are conduction, convection, and radiation. Conduction is the transfer of heat through direct contact between two objects, convection is the transfer of heat through the movement of fluids, and radiation is the transfer of heat through electromagnetic waves.

The rate of heat transfer by conduction is given by the equation Q = kA(ΔT/L), where Q is the amount of heat transferred, k is the thermal conductivity of the material, A is the area of contact between the two objects, ΔT is the temperature difference between the two objects, and L is the distance between the two objects.

The rate of heat transfer by convection is given by the equation Q = hA(ΔT), where Q is the amount of heat transferred, h is the convection heat transfer coefficient, A is the surface area of the object, and ΔT is the temperature difference between the object and the surrounding fluid.

The rate of heat transfer by radiation is given by the equation Q = σA(T^4), where Q is the amount of heat transferred, σ is the Stefan-Boltzmann constant, A is the surface area of the object, and T is the absolute temperature of the object.

The greenhouse effect is the absorption of infrared radiation by greenhouse gases in the atmosphere, which causes the atmosphere to warm. Greenhouse gases include carbon dioxide, methane, and water vapor.

Heat capacity is the amount of heat required to raise the temperature of an object by 1 degree Celsius, while specific heat capacity is the amount of heat required to raise the temperature of 1 gram of a substance by 1 degree Celsius. Specific heat capacity is a property of a substance, while heat capacity depends on the mass of the object.

The formula for calculating the heat capacity of an object is C = m * c, where C is the heat capacity, m is the mass of the object, and c is the specific heat capacity of the material.

The formula for calculating the specific heat capacity of a substance is c = Q / (m * ΔT), where c is the specific heat capacity, Q is the amount of heat transferred, m is the mass of the substance, and ΔT is the change in temperature.