# What is the formula for sound?

70 decibels is as loud as a washing machine or a dishwasher. It is a moderate noise level. 70 dB noise is not considered harmful to human hearing. However, extended exposure to levels above 55-60 dB can be considered disturbing or become annoying.

## How do you calculate sound in physics?

Sound intensity can be found from the following equation: I=Δp22ρvw. Δ p – change in pressure, or amplitude ρ – density of the material the sound is traveling through vw– speed of observed sound. The larger your sound wave oscillation, the more intense your sound will be.

## What are the 3 factors affecting sound?

• Nature of Material/ Medium.
• Temperature.
• Humidity of Air.

• Can sound waves generate heat?
• Can wind travel faster than the speed of sound?
• Does sound travel faster in space?
• How does sound going slower in water make it hard to talk to someone underwater?
• What psychological effect makes notes on a piano that are an octave apart sound the same?

## What is the intensity of a 70 dB sound?

The loudness of a sound is measured in decibels. The decibel level of a sound is given by the formula D = 10 log (I/I0 ), where D is the decibel level (dB), I is its intensity in watts per square meter (W/m2 ), and I0 = 10−12 W/m2 is the intensity of a barely audible “threshold” sound.

## How do you calculate loudness?

The speed of the sound depends on the density and the elasticity of the medium through which it travels. In general, sound travels faster in liquids than in gases and quicker in solids than in liquids. The greater the elasticity and the lower the density, the faster sound travels in a medium.

## How do you calculate dB?

1. Comparing Sound Power and Sound Pressure.
2. The dB Pressure Scale.
3. Comparing Two Pumps for Noise.
4. dB power = dB pressure + 20 log distance (feet) – 2.5 dB.
5. Solution: dB power = 87 + [20 × 0.954] – 2.5 = 103.58 dB.
6. dB pressure = dB power – 20 log distance (feet) + 2.5 dB.

## What properties affect sound?

The speed of sound in a medium is determined by a combination of the medium’s rigidity (or compressibility in gases) and its density. The more rigid (or less compressible) the medium, the faster the speed of sound. The greater the density of a medium, the slower the speed of sound.

## What affects speed of sound?

P waves travel fastest and are the first to arrive from the earthquake. In S or shear waves, rock oscillates perpendicular to the direction of wave propagation. In rock, S waves generally travel about 60% the speed of P waves, and the S wave always arrives after the P wave.

## What things affect sound?

• Effect of pressure (at constant temp)
• Effects of temperature. Since the velocity of sound in gas,
• Effect of density. At constant pressure,
• Effect of humidity.
• Effect of wind.
• Effect of frequency wave length & amplitude.

## Which waves are fastest?

Longitudinal waves A longitudinal wave is one where all the particles of the medium (such as gas, liquid or solid) vibrate in the same direction as the wave. Sound waves are longitudinal waves. When longitudinal waves travel through any given medium, they also include compressions and rarefactions.

## What are 10 facts about sound?

• Sound cannot travel through space since there are no molecules to travel through.
• Do you know what is louder than a car horn?
• The loudest natural sound on earth is caused by an erupting volcano.
• Dogs are capable of hearing sounds at a much higher frequency than humans can.

## What type of waves are sound waves?

Since this energy can be measured, the most common SI unit of sound that is used is Decibel which is abbreviated as dB. This unit is basically used to express the ratio of some value of a physical property to another, mainly on a logarithmic scale. This is called as Decibel Scale or DB Scale.

## What is the SI unit of sound?

The speed of sound varies depending on the temperature of the air through which the sound moves. On Earth, the speed of sound at sea level — assuming an air temperature of 59 degrees Fahrenheit (15 degrees Celsius) — is 761.2 mph (1,225 km/h).

## What is the real speed of sound?

decibel (dB), unit for expressing the ratio between two physical quantities, usually amounts of acoustic or electric power, or for measuring the relative loudness of sounds. One decibel (0.1 bel) equals 10 times the common logarithm of the power ratio.

## What is dB in sound?

Common Sources of Noise and Decibel Levels A whisper is about 30 dB, normal conversation is about 60 dB, and a motorcycle engine running is about 95 dB. Noise above 70 dB over a prolonged period of time may start to damage your hearing. Loud noise above 120 dB can cause immediate harm to your ears.

## How far does sound travel per second?

The speed of sound through the atmosphere is a constant that depends on the daily temperature. On a standard day at sea level static conditions, the speed of sound is about 760 mph, or 1100 feet/second.

## What’s the speed of sound in water?

The speed of sound in air under typical conditions is about 343 meters per second, while the speed of sound in water is about 1,480 meters per second.

## What is the speed of sound in air at 0 C?

The speed of sound in dry air at a temperature of 0 degree C is approximately 344 m/sec (1130 ft/sec).

## How loud is hearing damage?

80 decibels is fairly loud. It’s equivalent to the noise of a busy downtown street. Being loud, it is a noise level that may harm your hearing if you are exposed to it for longer periods (more than 8-10 hours/day).

## Is 80dB loud?

The size of the vibration (also called amplitude) determines the volume. The amplitude of the vibration carries the energy. A big vibration causes large sound waves that transmit a lot of energy. The resulting volume of sound is loud – for example, a balloon bursting or a dog barking.

## What makes sound louder than other?

As distance from the sound source increases, the area covered by the sound waves increases. The same amount of energy is spread over a greater area, so the intensity and loudness of the sound is less. This explains why even loud sounds fade away as you move farther from the source.

## How does sound decrease with distance?

The intensity of a wave is defined as I=P4πr2 I = P 4 π r 2 . Intensity: Power output per unit area. The standard unit for intensity is Watts per square meters (Wm2) ( W m 2 ) .

## What is the formula of intensity of wave?

As a sound wave carries its energy through a two-dimensional or three-dimensional medium, the intensity of the sound wave decreases with increasing distance from the source.