-
SUP-8.2-L1 | Music Instruments
-
SUP-8.2-L2 | Hertz Vs Decibel
-
SUP-8.3-L1 | Sound and Hearing
-
SUP-8.3-L2 | Hundred Decibels - Science of Sound Waves - Resources
-
SUP-8.5-L1 | Science of Motion Pictures - Build a Zoetrope
-
SUP-8.5-L2 | Magic vision - Resources
-
SUP-8.7-L1 | Locate your favorite Star
-
SUP-8.7-L2 | Graph your constellations
-
SUP-8.7-L4 | Astro - Know your stars - Resources -Rangers
Stars are huge celestial bodies made mostly of hydrogen and helium that produce light and heat from the churning nuclear forges inside their cores. Aside from our sun, the dots of light we see in the sky are all light-years from Earth. They are the building blocks of galaxies, of which there are billions in the universe. It’s impossible to know how many stars exist, but astronomers estimate that in our Milky Way galaxy alone, there are about 300 billion. Lets learn more about Sun and Stars
-
SUP-6.5-L1 | Persistence of Vision - Motorised mechanism
-
SUP-7.8-L1 | Time and Measurement
-
SUC-7.1-L1 | Home made Thermodynamics - from Household Materials
- Objectives
- Engage – Basics of Thermodynamics
- Explore Kelvin Scale
- Explore – Underwater Volcano
- Elaborate – Make your own Solar updraft tower
- Explain – How does a Solar Updraft tower work?
- Evaluate- Quiz
- Protected: Home made refrigerator
- Protected: How does refrigerator work
- Protected: Freezing point and melting point
- Protected: Boilng point and Condensation point
- Protected: Paper Kettle
Engage – Hertz and Decibel
HERTZ and DECIBEL.
What is Hertz?
Hertz is the unit for measuring the frequency of sound waves. We know that sound travels in the form of waves. So frequency is the number of waves that pass through a fixed point in unit time. Hertz is the derived unit of frequency in the International System of Units and is defined as one cycle per second. It is named after Heinrich Rudolf Hertz, the first person to provide conclusive proof of the existence of electromagnetic waves.
One hertz simply means “one cycle per second” 100 Hz means “one hundred cycles per second”, and so on. The unit may be applied to any periodic event—for example, a clock might be said to tick at 1 Hz, or a human heart might be said to beat at 1.2 Hz.
The dimension of the unit hertz is 1/time (1/T). Expressed in base SI units it is 1/second (1/s)
Explore More:
Tone, in acoustics, sound that can be recognized by its regularity of vibration. A simple tone has only one frequency, although its intensity may vary.
The tone generator can play the sounds of four different waveforms. Simply enter your desired frequency and press play. Click on the buttons to select which waveform you would like to generate.
https://onlinetonegenerator.com/
What is Decibel?
Decibel is the measurement of how loud the sound is. It is the unit for comparing the loudness of two different sounds. The decibel is a relative unit of measurement corresponding to one tenth of a bel. It is used to express the ratio of one value of a power or root-power quantity to another, on a logarithmic scale.
Relation between hertz and decibel
The relationship between Hertz and decibels allow a listener to measure the frequency and perceived loudness of any sound.
Sound is a travelling longitudinal wave which is an oscillation of pressure. The frequency of air pressure change in a vibration is measured in Hertz. The resulting change in air pressure, created through the vibrating object is measured in decibels. Decibels, in effect, measures the loudness of a sound and Hertz measures the frequency of the sound.
Difference between hertz and decibel
Hertz is used to measure frequency, but decibel is used to measure intensity level.
Hertz is an absolute unit, which does not depend on external factors. Decibel is dependent on the reference intensity as well as the multiplication factor at the beginning of the equation.
The definition of decibel changes depending on the type of wave, but the definition of the hertz is valid for every situation. Hertz has a basic dimension which is the inverse of the unit of time.[1/second (1/s) ]. Since decibel is a logarithmic value multiplied by a constant, it is a dimensionless value.