Energy Everywhere
What is Energy?
The ability to do work or cause change.
What are the three types of heat transfer?
Conduction, Convection, and radiation
What are the two main types of waves?
Transverse and longitudinal.
What type of wave is light?
An electromagnetic wave (transverse).
What type of wave is sound?
A mechanical (longitudinal).
Name two types of energy
Kinetic, Potential, Sound, Light, Heat,
How does conduction transfer heat?
Through direct contact between particles.
What is a wave?
A transfer of energy without transferring matter.
What is the law of reflection?
The angle of incidence = angle of reflection.
What medium does sound travel fastest through - air, water, or metal?
Metal
What is energy efficiency?
The ability to complete the same task with less energy.
Why does metal feel colder than wood at the same temperature?
Metal conducts heat away faster.
What does the frequency of a wave measure?
How many waves pass a point per second.
What happens when light passes through a convex lens?
The light bends and converges to a focus point.
Why can sound not travel through space?
There are no particles to vibrate.
What is waste energy? Give an Example.
Waste energy is energy that is not usefully transferred or transformed. Example: in a car engine, some energy is wasted as heat and noise instead of moving the car.
What happens to particles in a substance when it's heated?
They move faster and spread apart.
What happens to wavelength when frequency increases?
Wavelength gets shorter.
What is refraction and where does it occur?
Refraction is the bending of light as it passes from one medium to another.
What does the amplitude of a sound wave affect?
The loudness (volume)
An appliances uses 2,000 J of energy to produce 1,400 H of useful heat. Calculate the efficiency.
(1,400/2,000) * 100 = 70%
Describe how convection works in boiling water.
Hot water rises, cool water sinks, forming a convection current.
What is the difference between amplitude and wavelength?
Amplitude = wave height
Wavelength = distance between crests
Order the colours of visible light from longest to shortest wavelength.
Red, Orange, Yellow, Green, Blue, Indigo, Violet.
What is the doppler effect?
The change in frequency (pitch) of a sound as the source moves towards or away from the listener.