Thermal energy test study guide

Question 1

Temperature conversions (approximate)

Answer 1

F to C: F-30/2
C to F: Cx2+30
K to C: C+273
C to K: K-273

Question 2

Heat

Answer 2

Heat is the transfer of thermal energy from a higher temperature object or location to a lower temperature object or location

Question 3

Thermal equilibrium

Answer 3

The condition under which two substances in physical contact with each other exchange no heat energy

Question 4

Temperature

Answer 4

• is directly proportional to the average kinetic energy of an object’s molecules
• the more kinetic energy the molecules have, the higher the temperature

Question 5

Conduction

Answer 5

• Conduction: transfers through direct contact
• occurs most easily in solids because their molecules are closer together.

Question 6

Convection

Answer 6

heat transfer from one location to another by the movement of liquids and gasses is known as convention

Question 7

Radiation

Answer 7

heat transfer by EM waves through empty space or matter is known as radiation

Question 8

Thermal contraction

Answer 8

As the temperature of a substance decreases, its molecules slow down and lose kinetic energy

Question 9

Thermal expansion

Answer 9

as temperature of a substance increases, its molecules pick up speed and gain KE ; the increase in KE causes the molecules to spread farther apart and the substance expands

Question 10

Kinetic energy

Answer 10

an object in motion

Question 11

Potential energy

Answer 11

Stored energy in an object due to the object’s position

Question 12

Mechanical

Answer 12

The energy of an object due to its motion and position, Usually used to describe a large object.

Question 13

Thermal energy

Answer 13

• Thermal energy is the total kinetic energy associated with all molecules in a substance
• Thermal energy and temperature are NOT the same became temperature only considers the average KE of molecules

Question 14

Conductors

Answer 14

• Materials that are good conductors have atoms with “ loose “ electrons that
• conductors can bump into other atoms and easily transfers thermal energy.
• silver
• aluminum
• copper
• water

Question 15

Insulators

Answer 15

• Insulators are materials that transfer heat poorly. Insulators are usually porous materials with air spaces that act to reduce the transfer of heat. Good insulators are usually poor conductors.
• glass
• plastic
• wood
• air

Question 16

Fahrenheit, Celcius, and Kelvin

Answer 16

• Fahrenheit - used primarily in the United States
• Celsius - Used primarily everywhere else in the world
• Kelvin - is based on absolute zero, the lowest temperature something can have. Commonly used by Scientists

Question 17

1st law of thermodynamics

Answer 17

• The 1st law of thermodynamics is following the law of conservation of energy
• Energy cannot be created or destroyed, only converted from one form to another

Question 18

2nd law of thermodynamics

Answer 18

The 2nd law of thermodynamics states that heat normally does from high temperature to low temperature.

Question 19

Specific heat

Answer 19

• Specific heat is the amount of heat needed to raise the temperature of 1 gram of a substance by 1℃ (or kelvin)
• The units for specific heat are joules per gram per ℃ (or kelvin)