Energy On The Move
Ability to do work
Energy
Energy of motion is called what?
Kinetic energy
Name three forms of energy
kinetic, thermal, chemical, electrical, light,
Maya pours hot coffee into a ceramic mug. After several minutes, the mug becomes warm, and the air directly above the coffee also becomes warmer.
Identify the thermal energy transfer occurring.
A student holds an ice cube in their hand. The ice cube begins melting, while the student's hand feels colder.
In which direction is thermal energy being transferred? Explain
Thermal energy is transferred from the student's warmer hand to the colder ice cube. The ice absorbs energy, causing it to melt, while the hand loses thermal energy and feels colder.
What type of energy is stored in food?
Chemical Energy
If an object speeds up, what happens to its kinetic energy?
Kinetic energy increased
A metal spoon and a plastic spoon are placed in the same cup of hot water. The metal spoon's handle becomes hot much faster. The water is at the same temperature around both spoons. What property best explains the difference?
Thermal conductivity. Metal transfers thermal energy through conduction much more effectively than plastic.
A student places bread in a toaster. Electrical energy enters the toaster, the heating elements glow, and the bread becomes hot and eventually toasted.
What are the energy transfers occuring?
Electrical energy → thermal energy, which is transferred to the bread.
Sun to Carrot
What type of energy was transferred?
_____ -> ________
Light to Chemical Energy
What law states that energy cannot be created or destroyed?
Law of conservation of energy
What type of energy transfer occurs when you touch a hot pan?
Thermal Energy
A tank contains water. A heater is placed on the right side near the bottom. After several minutes, describe the general circulation pattern you would expect and explain why.
Water near the heater becomes warmer and less dense, so it rises. Cooler, denser water moves downward and toward the heater, creating a circulating convection current.
A flashlight contains batteries. When switched on, the bulb produces light, but the flashlight also becomes slightly warm
What type two types of energy is used
_____ -> ________
Chemical energy stored in the battery is converted into electrical energy, which becomes light and thermal energy
Eating ice cream then going to ride a bike
What type of energy is being transferred?
______ -> _______
Chemical Energy to mechanical energy
What type of energy is stored in a remote battery
Chemical Energy
What energy transfer occurs when the Sun warms Earth?
Radiation
A pot of water is boiling. Thermal energy travels through the metal bottom of the pot and then spreads through the water.
Identify the correct thermal energy transfer used.
Conduction occurs through the metal because energy is transferred through particle interactions. Convection occurs in the water because the fluid itself moves, transporting thermal energy.
1)Sunlight travels through space and warms a sidewalk on Earth.
2)Later, the sidewalk warms the air touching it,
3) and the warmed air rises.
Identify the sequence of energy-transfer mechanisms with each scenario
Radiation: Sun → sidewalk
Conduction: sidewalk → air touching it
Convection: warm air rises and transfers thermal energy
What form of energy is associated with the movement of particles?
Thermal energy
What process transfers thermal energy through the movement of fluids?
Convection
A student claims, "If two objects have the same temperature, conduction cannot occur between them." Is this statement scientifically valid? Explain.
Yes, if the objects are in thermal equilibrium and there is no temperature difference between them, there is no net heat transfer.
An electric fan is plugged into an outlet. After it is turned on, the blades rotate and air begins moving. After running for an hour, the motor is warm.
Describe at least three energy transfers occurring in this system.
Electrical energy → mechanical energy in the rotating motor and blades; mechanical energy is transferred to the moving air; some electrical energy is converted to thermal energy in the motor and wires