is plastic and wood a
A. insulators
B. conductors
C. radiators
D. metalloids
A. insulators
Convection does NOT occur in
A. gases
B. liquids
C. solids
D. fluids
C. solids
Radiation allows heat to travel through empty space (a vacuum) without a medium.
*
A. True
B. False
A. True
Metal spoon transferring heat from pot to you.
A. Conduction
B. Convection
C. Radiation
A. Conduction
Hot air _____________ and cold air _____________ due to ___________.
Hot air rises and cold air sinks due to convection.
are you sure?
Yes, I am sure. Hot air has lower density compared to cold air, which causes it to rise. This movement of air due to differences in density is known as convection.
Conduction happens when:
*
A. molecules vibrate quickly bump into other molecules, which transfers heat
B. heat is transferred by physical touch
C. free electrons collide with atoms which cause faster vibrations
D. all of the above
D. all of the above
Lashonte was studying mechanical energy in science class. She noticed several possible examples of mechanical energy in her environment. Which of the following is NOT an example of mechanical energy?
*
A. a garden hose with moving water
B. music playing on your phone
C. a windmill moving in the wind
D. a lamp giving off light
D. a lamp giving off light
Kyra and Violet are camping with their family. They are roasting marshmallows over a campfire. What types of energy are released by the camp fire?
*
A. mechanical energy and magnetic energy
B. heat energy and light energy
C. nuclear energy and electrical energy
D. chemical energy and sound energy
B. heat energy and light energy
When energy is conserved or transferred, some energy becomes unavailable to do useful work. What happened to the unavailable energy?
*
A. It is conducted.
B. It is completely destroyed.
C. It is given off as heat.
D. It is given off as microwaves.
C. It is given off as heat.
An electric fan is plugged into an outlet and the circuit completed, making the fan blades spin. Which of the following correctly describes this situation?
*
1 point
A. Electrical energy is transformed into mechanical energy.
B. Mechanical energy is transformed into electrical energy.
C. Mechanical energy is destroyed, and electrical energy is created.
D. Electrical energy is destroyed, and mechanical energy is created.
A. Electrical energy is transformed into mechanical energy.
What determines an object's kinetic energy?
*
1 point
A. Mass and speed
B. Weight and speed
C. Mass and position
D. Weight and position
A. Mass and speed
Potential Energy is the energy of:
*
1 point
A. motion
B. mass
C. speed
D. position
D. position
The kinetic and potential energies of an object both always depend on which property?
*
1 point
A. mass of the object
B. volume of the object
C. relative position of the object
D. gravitational force of the object