Thermal Energy

Energy transferred from a higher temperature object to a lower temperature object is ___.

• heat

• kinetic energy

• thermal energy

• internal energy

Which is the sum of the kinetic and potential energies of an object?

• Heat energy

• Specific heat capacity

• Thermal energy

• Temperature

Two isolated objects, at different temperatures, are put in contact with each other. Which of the following is/are true when the system reaches thermal equilibrium?

I. The cool object gains the same amount of heat lost by the warm object.

II. Both objects will have the same final temperature

III. Both objects lose the same amount of heat

• I ONLY

• II ONLY

• I AND II ONLY

• I AND III ONLY

Which best describes temperature?

• It is equal to the heat difference between two objects

• It is proportional to the total energy in an object

• It is proportional to the average kinetic energy of particles in an object

• It is equal to an object’s specific heat capacity

Two beakers A & B contain water at a temperature of 40°C. A contains 100 g of water and B contains 250 g of water. Which of the following statements is true about them?

I. has less thermal energy than

II. Both A and B have the same thermal energy

III. The water molecules in both A and B have the same average kinetic energy

• I ONLY

• II ONLY

• III ONLY

• I AND III ONLY

Which thermal exchange process does not require a medium?

• conduction

• convection

• radiation

• evaporation

Which thermal exchange process carries thermal energy through boiling water as it heats on top of a stove?

• Conduction

• convection

• radiation

• evaporation

A solid bar is heated at one end. How is thermal energy transferred to the other end of the bar?

• Heated molecules move along the bar, carrying energy to the other end

• Heated molecules move along the bar, giving energy to others along the bar

• Heated molecules stay completely still, but give energy to other molecules

• Heated molecules vibrate more rapidly and pass energy to other molecules

Samples of four different materials at room temperature are heated from below and heat is transferred upwards. In which material is all of the heat transferred by the vibration of molecules?

• air

• mercury

• rubber

• water

When a piece of smoldering rope is held at the opening of the box in the diagram, smoke moves in the direction indicated below.

• Convection

• Radiation

• Vibration of molecules

• Movement of free electrons