SCX physics Flashcards
millimeters
x 10E-3
micrometers
x 10E-6
nanometers
x 10E-9
picometers
x 10E-12
kilo
x 10E3
mega
x 10E6
giga
x 10E9
temperature
Average kinectic energy of particles in a substance
Heat
total kinetic and potential energy of the particles in a substance.
C to K
+ 273
-273
Conduction
heat transfer usually between 2 solids.
Conductors and insulators
Free flowing electrons in conductors and not many free flowing electrons in insulators (allowing flow of heat)
Direction of heat
Hot to cold (until reaches equilbrium)
Convection
Movement of heat between free flowing particles (liquids and gases)
radiation
Heat transfer where no particles are required (can travel in a vaccum)
Black
Shiny
White
- Absorbs/Emits most
-Absorbs/Emits least - Reflects most
Specific heat capacity
The amount of energy required for 1kg of a substance to have its temperature raised by 1 degree C
Q = mcΔT
Q = Joules (J)
m= mass (kg)
c = Specific heat capacity (Jkg-1C-1)
ΔT = Tf-Ti (C)
E = P/t
E = Energy (J)
P = Power (W)
t = Time (s)
Electromagnetic Spectrum
Radio Waves, Microwaves, Infrared, ROYGBIV, Ultraviolet, X rays, Gamma Rays
Longitudinal Waves
Waves which oscillate in the direction parallel to the direction of the wave.
Transversal Waves
Waves which oscillate perpendicular to the direction of the wave.
Radio Waves
- Communication (Radio and TV)
Microwaves
- Heating food
-Communication (Wifi, mbile phones, satellites)
Infrared
-Remote controls
- Fibre optic communication
- thermal imaging
- night vision
- motion sensors
Visible Light
- Photographs/videos
- Fibre optic communications
Ultraviolet
- Suntan
- Security marking
-Fluorescent bulbs
X-ray
- Medicine
-Airport security
Gamma rays
-Sterilising medical instruments
- Treating cancer
Photon
A massless packet or quantum of electromagnetic energy
Diffraction
The bending of a wave as it passes through a gap or around a barrier
Magnetic field
An area where a ferromagnectic metal or charge experiences a force
AC current
Alternating current is an electric current that periodically reverses direction.
Step up and step down transformers
A transformer is a device used to increase or decrease the voltage in a circuit.
Two coils of wire around a soft iron core use the concepts of electromagnetic induction to do this.
How does a AC generator generate electricity
An AC generator (alternator) converts mechanical energy into electrical energy using electromagnetic induction. Inside the generator, a coil of wire rotates within a magnetic field. As the coil spins, it cuts through the magnetic lines of force, which induces a current in the wire. Because the direction of motion changes every half turn, the induced current also reverses direction, producing an alternating current (AC). There are slip rings and brushes present to keep the circuit complete and to make sure the current continues to flow in the external circuit. The faster the coil spins, the greater the voltage generated, and this entire process follows Fleming’s Right-Hand Rule.
Nuclear Fission
Nuclear power plants generate electricity using nuclear fission, a process where heavy atoms like uranium-235 are split into smaller atoms, releasing a huge amount of heat energy. This heat is used to boil water, producing steam that spins a turbine, which drives a generator to produce electricity. The reaction takes place in a nuclear reactor, and control rods are used to manage the rate of fission, keeping the process stable and safe. Unlike fossil fuels, nuclear power doesn’t release carbon dioxide, making it a low-emission energy source.
