1 full transverse wave should consist one crest and one trough.
Longitudinal wave can be found in sound wave (when we talk or sing) and slinky wave.
1 full longitudinal wave should consist one rarefaction and one compression.
Some waves need medium to transmit, this waves are called mechanical waves, for example ocean wave need water while electromagnetic waves can be transmitted without medium, for example radio wave can work in the space.
There are many wave properties such as :
1. Frequency means number of waves in 1 second, in a radio you can know frequency by modulating its radio wave for example you can find Radio A at 92 MHz etc
2. Period means time needed for a complete wave to transmit
3. Amplitude means maximum or minimum distance that can be reach by a motion wave
4. Speed of wave means the speed of wave when it moves.
5. Wavelength means length of a full wave
From the picture below (a same motion of transverse wave, the left graph is describing its time when it moves, while the other is describing its distance when it moves), we can assume that :
a. The frequency is 0.25 Hz,
b. The period is 4 s
c. The amplitude is 6 cm
d. The speed of wave is 5 m/s
e. The wavelength is 20 m
Mathematically, we can see that the frequency is inversed to period that's why some people say that period is reciprocal to frequency.
Speed of wave can also be defined by speed of wave to travel as far as its wavelength at its period (or frequency) or speed of wave is equal to a multiplication of wavelength and frequency or wavelength divided by period.
When wave moves and finds obstacle, it will show some responses. This behavior of wave can be categorized as :
1. Reflection or bounce back of the wave when the wave hits barrier
2. Refraction or bending of wave due to different medium
3. Superposition or a coalition of two or more waves, it could be destructive wave or constructive wave
4. Diffraction or bending of wave through a slit or narrow aperture
Generally, we can divide wave into 2 parts based on their medium, mechanical wave for the wave that need medium to move and electromagnetic wave for the wave that able to move without medium. The electromagnetic wave can travel at the speed of 300.000.000 m/s in vacuum and will decrease in other medium. The electromagnetic wave is a transverse wave that has a varied wavelength, frequency and energy. The bigger the wavelength, the smallest the frequency and energy and respectively, the smaller the wavelength, the bigger the frequency and energy. The shortest wavelength in electromagnetic wave is the gamma ray and the longest one is the radio wave.
The radio wave can be used for transmitting radio and television.
The micro wave is widely used for communication and heating food.
The infra red can be used for thermal imaging and remote control.
The visible is the light that we see everyday, it has the colour of red, orange, yellow, green, blue, indigo and violet.
Ultraviolet` source mainly is sun, it can be used for sterilisation and triggering vitamin D.
X Ray is mostly used for medical in detecting bone and teeth.
Gamma is produced by radioactive reaction, it can be used for sterilisation and medical used (cancer treatment)
No comments:
Post a Comment