Physical Science: Chapter 16 Study Guide

Which one of the three forms of heat transfer involves waves that move through space?

Radiation - waves

Does conduction happen quicker in solids or gases? Why?

Solids, because the particles are closer together.

What is the definition of specific heat?

The amount of heat needed to raise temperature of one gram of material by one degree Celsius.

You've got an 80°C cup of coffee and a large pitcher of coffee at the same temperature. Which one, if any, has the higher temperature?

The large pitcher because it has more particles, both are at the same temperature

What does the majority of materials in the universe do?

The majority of materials in the universe contract in length when cooled and expand in the length when heated

Give examples of thermal energy transfer by Conduction.

The metal radiator in the classroom gets hot from the steam or hot from the water flowing through it. A pan on a stove.

You've got two cups of coffee, each with the same mass. One is at 80°C and the other is at 75°C. Which one, if any has more thermal energy? Which one, if any has the higher temperature?

The one at 80 degrees

Give examples of thermal energy transfer by Radiation.

The sun's rays warming up the earth; the air in the classroom getting warmed up by thermal energy radiating from the radiator.

When does Thermal Expansion occur?

Thermal Expansion occurs when particles move father apart as temperature increases

True or False: the third law of thermodynamics means that no heat engine will ever be 100% efficient

True

A notable exception to the above rule is what material?

Water

Older building are often heated by pumping either hot ________ or ________ through pipes into a radiator. Thermal energy is transferred to the metal of the radiator from the steam or hot water by?

Water or steam Convection

Most of the devices listed above use a fluid called?

a refrigerant

Who has more thermal energy, an iceberg or a hot cup of coffee? Explain your answer.

an iceberg because it has more mass and contains more particles

What do most heating systems use to distributer thermal energy in the rooms being heated?

convection

In the electric baseboard heaters, ___________ energy is converted to thermal energy in the coils which then heat the air near it by _____________ and _____________. This is called _________ ____________

electric conduction radiation forced air

Every material in the universe has it's particles more ________ when heated and move ________ when cooled.

faster and slower

Heat pump

is a device that reverses the normal flow of heat, making it flow from cold to hot.

Absolute Zero

is a reading of 0 degrees on the Kelvin scale and is the temperature at which all particle motion stops

Thermal Expansion

is an increase in the volume of a material due to temperature increase.

Temperature

is the hotness or coldness of an object. It is related to the average kinetic energy of the particles in the object

Thermal Energy

is the total potential and kinetic energy of an object. IT depends on mass, temperature, and phase.

Heat

is the transfer of thermal energy from one object to another. It always flows from hot to cold objects.

The second law of thermodynamics states that energy can flow from COLDER to HOTTER objects only if?

only if work is done on the system

Name two everyday examples of the device listed above:

refrigerator and air conditioner

Thermal energy that is not converted into work is called?

waste heat An example of this is the hot exhaust gases coming out the exhaust pipe on a car.

In keeping with the second law of thermodynamics, the heat pump does _____________ on the refrigerant which is what makes it possible to make heat flow from cold to hot

work

State the third law of thermodynamics

Absolute zero can never be reached

Why does a coat help keep you warm? Most coats work because they have pockets of?

Air

Give examples of thermal energy transfer by Convection.

Air in a room, water in a pan.

What are the three forms in which heat can transfer from one object to another?

Conduction, convention, and radiation.

Which one of the three forms of heat transfer involves objects that are in direct contact with one another in which no matter actually moves?

Conduction, if they touch.

What do we call a material that allows heat to easily flow through it? Give some example materials.

Conductor, most metals

Which one of the three forms of heat transfer involves fluids that heat up, expand, and rise?

Convection - current, rising and falling

What do you call a looping flow caused when fluids heat, expand, rise, cool, and sink back down?

Convection current.

Are materials with relatively low specific heats easy to heat up or difficult to heat up?

Easy to heat up.

Some houses and apartments built in the latter half of 1900's use a device similar to a toaster along the wall to provide heat. What are these called?

Electric baseboard heaters

What does the first law of thermodynamics state?

Energy is conserved.

If a material is hard to hear up, is it easy or hard to cool down?

Hard to cool down.

What is a device that converts heat into work called?

Heat engine

What unit is heat measured in and what is it's symbol?

Heat is measured in joules. Heat = Q

Does water have a relatively high or relative lower heat?

High specific heat.

What do we call materials that DO NOT allow heat to flow through them? Give some example materials.

Insulators, air, wood, and wool

What is another name for the first law of thermodynamics?

Is the law of conservation of energy

As an object's temperature increases, what happens to the rate at which it radiates energy?

It increases.

Do metals tend to have high or low specific heats?

Lower specific heats.