Heat, Work and Energy

Heat, Work and Energy

By Claudine Francisco

Multiple Choice

A cup and a drop of boiling water have the same ______________ of 100º Celsius. (It is the measure of the hotness and coldness of a body.)

• temperature

• Thermal

• Internal

• Work

Multiple Choice

The ocean and a cup of seawater may have the same temperature but different ______________ energy. (It is the energy associated with the random motion of all molecules in a substance.)

• Heat

• Thermal

• Internal

• Work

Multiple Choice

When two objects having different temperatures are placed in contact with one another, ______________ flows from the hot object to the cold object. (It is the energy in transit from a body of higher temperature to a body of lower temperature.)

• Heat

• Power

• Internal

• Work

Multiple Choice

Matter does not contain heat; rather it contains ______________ energy. (It is the total of the potential and kinetic energies of the molecules of a substance.)

• Force

• Power

• Internal

• Work

Multiple Choice

As the water boils, the lid of the pot brings to move up. We say the air inside has done ______________ on the lid as it pushes the lid upward. (It is the product of the force on an object and the distance through which the object is moved.)

• Force

• Power

• External

• Work

Thermodynamics

Thermodynamics is the study of heat and its transformation to mechanical energy.

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Mechanisms of Heat Transfer

is a method of transferring heat within a body or two bodies that are in contact with each other.

Conduction

allows heat to be transferred through the motion of fluids such as air or water

Convection

happens when any form of electromagnetic radiation is emitted or absorbed.

Radiation

First Law of Thermodynamics

“Energy cannot be created nor destroyed. It can only be transformed into another

form, but the total amount of energy remains the same.”

Multiple Choice

A system does no work even when heat is added to it. Which of the following may happen to the system?

• The system expands

• The internal energy of the system increases

Multiple Choice

Which of the following is TRUE about thermodynamics?

• It deals with energy.

• It discusses the direction of heat movements.

• It is based on the conservation principle.

• All of the choices

Multiple Choice

The heat added to a system is used to increase the system’s _____________.

• pressure

• work input

• internal energy

• All of the choices

Multiple Choice

The first law of thermodynamics is a restatement of what conservation principle?

• Law of conservation of mass

• Law of conservation of energy

• Law of conservation of charges

• Law of conservation of momentum

Multiple Choice

If 5 J of energy is added to a system that does no external work, by how much will the internal energy of that system be raised?

• 0 J

• 5 J

• 10 J

• Cannot be determined