Thermodynamics Problems

What is the First Law of Thermodynamics?

• Energy can be created out of nothing

• Energy cannot be created or destroyed, only transformed from one form to another.

• Energy can be destroyed completely

• Energy can only be transformed into one specific form

Explain the concept of heat transfer and give an example.

• Heat transfer is when a frozen ice cube placed in a glass of water becomes colder due to the transfer of coldness from the water to the ice cube through radiation.

• An example of heat transfer is when a metal spoon placed in a hot cup of coffee becomes hot due to the transfer of heat from the coffee to the spoon through conduction.

• An example of heat transfer is when a person feels cold after standing near a bonfire due to the transfer of cold air from the bonfire to the person through convection.

• Heat transfer is when a metal spoon placed in a hot cup of coffee becomes cold due to the transfer of coldness from the spoon to the coffee through conduction.

Calculate the specific heat capacity of a substance if 500 J of heat is required to raise the temperature of 2 kg of the substance by 5°C.

• 10 J/kg°C

• 50 J/kg°C

• 100 J/kg°C

• 250 J/kg°C

Define internal energy in the context of thermodynamics.

• The energy transferred between a system and its surroundings

• The energy associated with the motion of an object

• The total energy contained within a system, including the kinetic and potential energy of its particles.

• The energy contained within a closed system, excluding potential energy

Discuss the different methods of heat transfer and provide examples of each.

• Reflection, absorption, and transmission

• Conduction, convection, and radiation are the three methods of heat transfer. Examples include a metal spoon getting hot when placed in a hot liquid (conduction), boiling water in a pot (convection), and feeling the warmth of the sun on your skin (radiation).

• Insulation, ventilation, and circulation

• Evaporation, condensation, and sublimation

A 2 kg block of metal absorbs 1000 J of heat and its temperature increases by 20°C. Calculate the specific heat capacity of the metal.

• 50 J/kg°C

• 25 J/kg°C

• 10 J/kg°C

• 15 J/kg°C

Explain the difference between heat and temperature.

• Heat and temperature are the same thing

• Heat is the transfer of energy, while temperature is a measure of the average kinetic energy of particles.

• Heat is a measure of the average kinetic energy of particles, while temperature is the transfer of energy

• Temperature is the transfer of energy, while heat is a measure of the average kinetic energy of particles

A gas undergoes a process in which 400 J of heat is added to it and 200 J of work is done by the gas. Calculate the change in internal energy of the gas.

• 0 J

• 200 J

• 100 J

• 500 J