Physics Flashcards
Transverse Wave
The vibrations are at right angles to the direction of travel. (Eg. Radio Waves and Light Waves)
Longitudinal Wave
The vibrations are parallel to the direction of the wave Travel in a straight line forwards and backwards (Eg. Sound Waves)
Mechanical Waves
Cause oscillations of particles in a solid, liquid or gas and must have a medium to travel through.
Electromagnetic waves
Cause oscillations in electrical and magnetic fields.
Rest position
The undisturbed position of particles or fields when they are not vibrating.
Displacement
The distance that a certain point in the medium has ,over from its rest position.
Peak
The highest point about the rest position. (Highest point of the wave)
Trough
The lowest point of the rest position. (Lowest point of the wave)
Amplitude
The maximum displacement of a point of a wave from its rest position. (The distance between the rest position and the peak of the wave)
Wavelength
Distance covered by a full cycle of the wave, usually measured from peak to peak, or trough to trough. Can also be measured by every second rest position.
Time period
The time taken for a full cycle of the wave, usually measured from peak to peak, or trough to trough. Can also be measured from every second rest point/position.
Frequency
The number of waves passing a point each second.
Time period of a wave calculation
Time period = 1/frequency (T=1/f)
Time period = seconds (s)
Frequency = Hertz (Hz)
Wave speed calculation
Wave speed = frequency x wavelength
Wave speed = v (metres per second (m/s))
frequency = f (Hertz (Hz))
Wavelength = weird looking a (Metres (m)
Conduction
When two regions at different temperatures come into contact, the hotter region transfers some of its thermal energy to the colder region. This gives the colder region more energy to vibrate and become hotter.
Convection
When a fluid is heated, its particles gain energy and vibrate (move) faster, causing the to spread out and become less dense. Warmer fluids and gasses rise because of their energy whilst colder fluids and gasses sink because of their lack of energy.
Radiation
Unlike convection and conduction, radiation does not require a medium to transfer heat. Heat energy can be emitted in the form of electromagnetic waves, such as infrared radiation, and can travel through empty space.
Heat
A form of energy transfer. Measured in Kinetic Energy (Kn)
Temperature
Refers to the measure of average kinetic energy. Measured in Celsius.
Medium
The material which a wave travels through is referred to as ‘A Medium’. Gasses (Eg. Air), Liquids (Eg. Water) and Solids (Eg. Ropes) all act as mediums that waves can travel through.
Define Refraction
Reflection is the bending of light waves. It occurs when a light ray moves from one medium into another medium with a different density.
