Energy
Describe the Law of Conservation of Energy.
The Law of Conservation of Energy states that energy cannot be created or destroyed, only changed from one form to another.
How does heat transfer stop when two objects reach the same temperature?
Heat transfer stops when both objects reach the same temperature, meaning thermal equilibrium is reached — no more net energy flow.
Why does a metal spoon get hotter than a plastic spoon in the same cup of soup?
A metal spoon gets hotter because metal conducts heat better than plastic — it transfers energy more efficiently.
What type of wave has the highest frequency on the electromagnetic spectrum?
The gamma ray has the highest frequency on the electromagnetic spectrum.
What two points define the wavelength of a transverse wave?
Crest to Crest or Trough to Trough
What is the difference between scientific law and scientific theory?
A scientific law describes what happens in nature (based on repeated observations).
A scientific theory explains why or how it happens.
What is an energy transformation?
An energy transformation is when energy changes form, such as potential → kinetic or electrical → light.
What happens to the speed of particles in a substance when its temperature increases?
When temperature increases, particles move faster and their kinetic energy increases.
What happens to light when it hits a mirror?
When light hits a mirror, it reflects — it bounces back at the same angle it came in.
What two points define the wavelength of a longitudinal wave?
Compression to Compression or Rarefaction to Rarefaction
What is the difference between kinetic energy and potential energy?
Kinetic energy = energy of motion.
Potential energy = stored energy due to position or condition.
Identify a scenario where kinetic energy is transformed into potential.
Example: When you throw a ball upward, kinetic energy (motion) transforms into potential energy (height).
B. Draw particles in: a. A solid (particles close together), b. A liquid (slightly spread), c. A gas (far apart, moving fast). Label which has the most thermal energy.
Solid: particles close together, vibrate in place
Liquid: particles slightly spread, slide past each other
Gas: particles far apart, move very fast
👉 Gas has the most thermal energy.
What kind of wave can travel through space?
An electromagnetic wave (like light) can travel through space because it does not need a medium.
The whole range of EM waves in order of increasing frequency and decreasing wavelength.
What is the role of energy transformation in the Law of Conservation of energy?
The Law of Conservation of Energy says energy cannot be created or destroyed — only transformed from one form to another.
Energy transformations make this possible.
Describe how energy is transformed when you turn on a flashlight.
In a flashlight, chemical energy in the batteries → electrical energy → light energy (and some heat).
A. Label where heat moves in this picture of a pot on the stove: 🔥 Flame, 🫕 Pot, 🌡 Water. Draw arrows showing conduction, convection, and radiation.
Pot on stove heat flow:
🔥 Flame → 🫕 Pot: Conduction (direct contact)
🫕 Pot → 🌡 Water: Convection (hot water rises, cool water sinks)
🔥 Flame → Pot (without touching): Radiation (heat transfer by waves)
What type of wave is sound?
Sound is a mechanical, longitudinal wave — it travels by vibrations moving through a medium (like air or water).
Why does sound travel faster in solids than in air?
Because the particles in solids are closer together, allowing vibrations to pass more quickly.
What is the relationship between potential and kinetic energy?
Potential energy is stored energy, while kinetic energy is energy of motion. They can change into each other.
Label a Roller Coaster: a. Circle where potential energy is greatest. b. Circle where kinetic energy is greatest. c. Draw arrows to show how energy transforms as it moves.
Top of the hill: greatest potential energy
Bottom of the hill: greatest kinetic energy
Arrows: show energy changing back and forth as it moves up and down.
How is the temperature of objects affected by heat flow?
Heat always flows from a warmer object to a cooler object until both reach the same temperature (thermal equilibrium).
What is a wave, and what does it transfer?
A wave is a disturbance that transfers energy from one place to another without transferring matter.
Compare and contrast mechanical and electromagnetic waves.
Mechanical: Needs a medium (sound, water waves).
Electromagnetic: Does not need a medium (light, X-rays).
Both transfer energy.