Flash Cards

Constantine Test Two

Term Definition
Wave A disturbance that transfers energy from place to place.
Medium The material through which a wave travels. Gas-Air Liquid-Water
Solid- Rope
Mechanical Waves Wave that requires a medium
What are the three types of waves? Transverse, longitudinal, surface
Transverse Wave A wave that moves a medium in a direction perpendicular to the direction in which the wave travels. Ex.: Making a wave with rope.
Crest Highest part of a wave.
Trough Lowest part of a wave
Longitudinal waves A wave that moves the particles of the medium parallel tot he direction that the waves are traveling.
Surface Wave Combinations of transverse and longitudinal waves. These have up and down motions combined with back and forth motions, yielding a circular motion.
What causes waves? A vibration.
Using a spring as an example, explain the compressions and rarefractions of a wave. When you push down it compresses and when you let go it causes rarefractions.
What are the properties of waves? Amplitude, wavelength, frequency and speed.
What is amplitude? The maximum distance the medium carrying the wave moves away from the rest position.
Define wavelength. The distance between two corresponding parts of a wave. You can measure crest to crest or trough to trough.
Define frequency. The number of complete waves that pass a fixed point in a certain amount of time. It is measured in units called Hertz (Hz).
What is speed? How far the wave travels in one unit of time. Speed= wavelength x frequency.
What happens to a wavelength when there is an increase in energy? The wavelength DECREASES and the frequency INCREASES.
What happens to a wavelength when there is a decrease in energy? The wavelength INCREASES and frequency DECREASES.
What is an electromagnetic wave? Transverse waves that transfer electric and magnetic energy. It consists of changing electric and magnetic fields. You can't see EM waves; only a small portion known as visible light can be seen.
What is light? Light is a form of electromagnetic energy which radiates as waves.
What is the electromagnetic spectrum? The range of electromagnetic waves placed in order of increasing frequency.
Do electromagnetic waves travel at the same speed, have the same wavelengths and frequencies? All EM waves travel at the same speed, but they have different wavelengths and frequencies.
What is the electromagnetic spectrum made up of? Radio waves, infrared rays, visible light, ultra-violet rays, X-rays and gamma rays.
What are radio waves? These are EM waves with the longest wavelengths and lowest frequencies. A radio receiver converts radio waves into sound waves you can hear.
What is RADAR? It stands for Radio Detection And Ranging. It can be used to locate objects. Police use this and the Doppler Effect to find the speeds of vehicles.
What electronic has the shortest radio waves and highest frequency? A microwave has the shortest waves and highest frequency.
What is a MRI? Magnetic Resonance Imaging, which uses radio waves used in medicine to produce pictures of tissues in the human body.
What are INFRARED RAYS? These have shorter wavelengths and higher frequencies than radio waves. You can feel these as warmth, and they are also called heat rays.
What is a thermogram? This is the picture a infrared camera takes. It shows regions of different temperatures in different colors.
What are UV rays? These are Ultraviolet Rays. These are EM waves with wavelngths just shorter than those of visible light. UV lamps are used to kill bacteria. Humans cannot see UV light, but many insects can.
What is VISIBLE LIGHT? This has shorter wavelengths and higher frequencies than infrared waves. The longest waves of visible light are ROYGBV.
What are X-Rays? These are EM waves with very short wavelengths. X-rays are used to take pictures of the human body, or pictures of objects used in industry and engineering.
What are gamma rays? These have the shortest waves and highest frequency on the EM spectrum. These are the most penetrating of all EM waves. They are used in medicine in radiation to kill cancer cells.