Types of Energy
What is energy?
Energy is the ability to do work or cause change.
What are the three types of heat transfer?
Conduction, convection, and radiation.
What causes sound to be produced?
Vibrations that create disturbances in a medium, transferring energy to our ears.
What is an aerophone? Give an example.
An instrument that produces sound by vibrating air; example: didgeridoo.
What is light made of?
Photons, which are particles of electromagnetic energy.
What is static electricity?
A build-up of electrical charge on a surface, often due to friction.
Which model helps us explain conduction and convection?
The particle model.
Give two examples of energy being transformed.
A toaster transforms electrical energy into heat; a light bulb transforms electrical energy into light
What is conduction?
Heat transfer directly between neighboring atoms or molecules, usually through a solid.
What is a longitudinal wave?
A wave where the vibration is in the same direction as the wave travels; sound waves are longitudinal.
What is an idiophone? How does it make sound?
An instrument that produces sound from the material itself vibrating; example: clapsticks.
What are the two models used to describe light?
Wave model and particle (photon) model.
Name three parts of an electrical circuit.
Energy source (e.g., battery), energy user (e.g., light bulb), and conducting wires.
What happens to particles when heat is added?
They move faster and spread apart.
What is the difference between energy transfer and energy transformation?
Energy transfer is moving the same type of energy from one object to another; energy transformation is changing energy from one type to another.
What is convection? Give an example.
Heat transfer via the movement of a fluid, such as air or water; for example, boiling water.
Which medium does sound travel fastest through: solid, liquid, or gas?
Solid, because particles are more tightly packed.
What material is used in membranophones like skin drums?
Stretched animal skin, such as goanna or lizard skin.
What happens when light passes from air into water?
It slows down and bends, a process called refraction.
What is the difference between series and parallel circuits?
In series circuits, components share the same path; in parallel circuits, components are on separate branches.
Why is the particle model useful for understanding electricity?
It helps explain how electrons move through conductors and insulators.
In a hairdryer, name three types of energy involved.
Electrical energy is transformed into heat energy and kinetic energy; some energy is also transferred as sound.
How does radiation differ from conduction and convection?
Radiation is the emission of electromagnetic waves and does not require a medium to transfer heat.
What are compressions and rarefactions?
Compressions are regions of increased pressure; rarefactions are regions of decreased pressure in a sound wave.
How does circular breathing help when playing a didgeridoo?
It allows continuous sound production by inhaling through the nose while pushing air out through the mouth.
Define reflection and refraction.
Reflection is when light bounces off a surface; refraction is when light bends as it passes through a different medium.
What does a voltmeter measure?
The voltage, or potential difference, across components in a circuit.
How does the wave model explain sound movement?
Sound travels as longitudinal waves through a medium, compressing and rarefying particles.
Explain why no energy system is 100% efficient.
Because some energy is always lost to the surroundings, often as heat or sound, making the system less than 100% efficient.
Why are metals good conductors of heat?
Because their electrons are free to move, allowing them to transfer kinetic energy more readily.
Explain the relationship between amplitude and loudness.
Greater amplitude means louder sound; smaller amplitude means softer sound.
Why does a longer didgeridoo have a lower pitch?
Because longer air columns produce lower frequency vibrations, resulting in a lower pitch.
What is the difference between convex and concave lenses?
Convex lenses converge light rays; concave lenses diverge light rays.
List two factors that affect resistance in a wire.
Material of the wire and its length.
Compare how energy travels as waves vs particles in light and sound.
Light can travel as both waves and particles (photons) and doesn't need a medium; sound travels as waves and requires a medium.