Answer:
sound intensity is explained by the following formula I= P/A where I= sound intensity(W/m²),P=power(W),A= area(m²) I hope this helps good luck!
Answer:
In a quiet forest, you can sometimes hear a single leaf fall to the ground. After settling into bed, you may hear your blood pulsing through your ears. But when a passing motorist has his stereo turned up, you cannot even hear what the person next to you in your car is saying. We are all very familiar with the loudness of sounds and aware that they are related to how energetically the source is vibrating. In cartoons depicting a screaming person (or an animal making a loud noise), the cartoonist often shows an open mouth with a vibrating uvula, the hanging tissue at the back of the mouth, to suggest a loud sound coming from the throat Figure 2. High noise exposure is hazardous to hearing, and it is common for musicians to have hearing losses that are sufficiently severe that they interfere with the musicians’ abilities to perform. The relevant physical quantity is sound intensity, a concept that is valid for all sounds whether or not they are in the audible range.
Intensity is defined to be the power per unit area carried by a wave. Power is the rate at which energy is transferred by the wave. In equation form, intensity I is I=PAI=PA, where P is the power through an area A. The SI unit for I is W/m2. The intensity of a sound wave is related to its amplitude squared by the following relationship:
\(\displaystyle{I}=\frac{\left(\Delta{p}\right)^2}{2\rho{v}_{\text{w}}}\\\).
Here Δp is the pressure variation or pressure amplitude (half the difference between the maximum and minimum pressure in the sound wave) in units of pascals (Pa) or N/m2. (We are using a lower case p for pressure to distinguish it from power, denoted by P above.) The energy (as kinetic energy mv22mv22) of an oscillating element of air due to a traveling sound wave is proportional to its amplitude squared. In this equation, ρ is the density of the material in which the sound wave travels, in units of kg/m3, and vw is the speed of sound in the medium, in units of m/s. The pressure variation is proportional to the amplitude of the oscillation, and so I varies as (Δp)2 (Figure 2). This relationship is consistent with the fact that the sound wave is produced by some vibration; the greater its pressure amplitude, the more the air is compressed in the sound it creates
Sound intensity levels are quoted in decibels (dB) much more often than sound intensities in watts per meter squared. Decibels are the unit of choice in the scientific literature as well as in the popular media. The reasons for this choice of units are related to how we perceive sounds. How our ears perceive sound can be more accurately described by the logarithm of the intensity rather than directly to the intensity. The sound intensity level β in decibels of a sound having an intensity I in watts per meter squared is defined to be β(dB)=10log10(II0)β(dB)=10log10(II0), where I0 = 10−12 W/m2 is a reference intensity. In particular, I0 is the lowest or threshold intensity of sound a person with normal hearing can perceive at a frequency of 1000 Hz. Sound intensity level is not the same as intensity. Because β is defined in terms of a ratio, it is a unitless quantity telling you the level of the sound relative to a fixed standard (10−12 W/m2, in this case). The units of decibels (dB) are used to indicate this ratio is multiplied by 10 in its definition. The bel, upon which the decibel is based, is named for Alexander Graham Bell, the inventor of the telephone.
Table 1. Sound Intensity Levels and IntensitiesSound .
in the circuit diagram below on voltmeter V2 is 12V and the reading on ammeter A1 is 2A
calculate the amount of charge that flows through ammeter A1 in 120 second
Answer:
q = 240 C
Explanation:
The current passing through a circuit is defined as the amount of charge passing through that circuit per unit of time. Hence, the current can be calculated through the following formula:
[tex]I = \frac{q}{t}\\\\q = It[/tex]
where,
q = total amount of charge = ?
I = current = 2 A
t = time = 120 s
Therefore,
[tex]q = (2\ A)(120\ s)\\[/tex]
q = 240 C
What are two ways fission is used in the real world.
Answer:
germ cleaning
and getting up cooking grease
Explanation:
Simplify 45÷3+2×8-12+42
Answer:
Explanation is in the picture and the answer is 16
write your opinion about achievement made by during rana rule
Answer:
Your opinion about achievement made by during rana rule
Explanation:
April Fools !
What is the formula for Newton's
second law?
Answer:
f=ma
Explanation:
Answer:
F = m * a
Explanation:
2nd law of motion
PLZZZZ HELPPPPPP MEEEEEE!!!!!! ILL GIVE 20 POINTS AND BRAINLIEST!!!
:'(
I am desperate guys.
Answer:
c.
Explanation:
In positron emission, also called positive beta decay (β+-decay), a proton in the parent nucleus decays into a neutron that remains in the daughter nucleus, and the nucleus emits a neutrino and a positron, which is a positive particle like an ordinary electron in mass but of opposite charge.
Does this help? Sorry it's wordy that's just how my teachers taught me :'(
what does heat trapped by pollution cause?
A. Acid rain
B. Decomposition
C. Greenhouse effect
Answer:
C. Greenhouse Effect
Explanation:
The greenhouse effect is caused by heat trapping pollution in the atmosphere.
A catapult with a just-ejected ball flying through the air. A catapult's lever holds a cannonball. The lever is attached to a tightly held rope. When the rope is released, the lever springs forward and launches the cannonball. When the rope is held tightly, which form of energy does it possess? thermal nuclear gravitational elastic
Answer:
he string has POTENTIAL ELASTIC energy
Explanation:
he catapult is a very good example of energy transformations.
Initially when the string is taut it has an elastic potential energy, when releasing the lever it is transformed into cinetic energy in the ball until it shoots out.
Consequently the string has POTENTIAL ELASTIC energy
Answer:
The answer is elastic
TRUST ME
Explanation:
The prosecution has the responsibility to overcome the presumption of
Answer:
The presumption of 'innocence of defendant'
Explanation:
Prosecution refers to the conduct of legal proceedings against defendant (accused), for a criminal behaviour.
Prosecution has the responsibility to overcome the presumption of innocence of defendant, proving the latter guilty - based on supporting evidences.
Does anyone know the answer to all of these questions
Answer:
i don't understand the hw
Sound waves travel fastest through
Group of answer choices
water
air
a vacuum
steel
Answer:
Solids: Sound travels fastest through solids. This is because molecules in a solid medium are much closer together than those in a liquid or gas, allowing sound waves to travel more quickly through it. In fact, sound waves travel over 17 times faster through steel than through air.
Explanation:
Answer:
option number 3
a vaccummm
Please I really need this !! Potassium loses electrons when it reacts with oxygen. Which statement is true of potassium in this reaction?
A. It reduces.
B. It undergoes synthesis.
C. It undergoes redox.
D. It oxidizes
Research and define pressure, as it relates to air or water pressure.
Answer:
PRESSURE is a force exerted by the substance per unit area on another substance.
The key difference between water pressure and air pressure is that one is made up of water and the other is made up of air. Both air pressure and water pressure are based on and follow the same physical principals.
Explanation:
What is the “Food cam” at MIT? What is it for?
Answer:
But in MIT's Media Lab, everyone has a fair shot, thanks to a camera that alerts the lab when there's free food. Called the Foodcam, it features a camera that beams a photo of the leftovers to the entire lab, creators Will Glesnes and Jon Ferguson, tell Tech Insider.
How do you get DC current and AC current? from a generator?
Answer:
They do that by converting rotating mechanical energy into electrical power. Portable generators use an engine—typically running on gasoline, diesel, or propane, to turn an alternator which produces alternating electrical current or AC.
HOW TO ANSWER THIS QUESTION PLEASE
Answer:
radioactive decay is a random processuse long tongsExplanation:
Quantum theory has taught us that virtually everything to do with the nature of matter in the universe is a random process. The decay of atomic nuclei is something that makes that randomness "visible" with appropriate instrumentation. As such, the rate of decay will vary over the "short" term. Consequently, it is not surprising to see a variation of a few counts in an activity measurement over a period of a few minutes.
__
Safety with respect to radioactive materials involves staying as far away from them as possible. The use of long tongs for handling would be appropriate.
Answer:
Radioactive decay is a long proxyUse long tongs↔ for safety precautions the scientist should used this upon working with radioactive materials in a laboratory.
PLS HELP !!
Which of these must be true for a perfectly elastic collision?
Select one:
A: Kinetic energy is conserved
B: The velocity of the first object will not transfer to the second object
C: The objects will stick together
D: The masses must be equal
Answer:
D.
Explanation:
the masses must be equal
A high diver dives off a platform and strikes the water 1.857 seconds later. Ignoring air resistance, how fast is he traveling as he strikes the water in m/s?
Answer:
The (vertical) speed of the driver as he strikes the water is approximately 18.22 m/s
Explanation:
From the parameters given in the question, we have;
The time after which the driver strikes the water after he drives off a platform, t = 1.857 s
Let 'v' represent the vertical speed of the driver
We can find the vertical speed of the vehicle as it strikes the water as follows;
v = u + g·t
Where;
v = The final vertical velocity of the driver
u = The initial vertical speed of the driver = 0 m/s
g = The acceleration due to gravity ≈ 9.81 m/s²
t = The time of motion = 1.857 seconds
Therefore, we have;
v = 0 + 9.81 m/s² × 1.857 s = 18.21717 m/s
Therefore;
The vertical speed of the driver as he strikes the water, v ≈ 18.22 m/s
only a relatively small part of the electromagnetic spectrum is visible. what determines which bands of the electromagnetic spectrum are invisible to humans?
Answer:
hsnzbssj
Explanation:
skibbbbbbbbbbbbibi1. Find the current in a circuit where the voltage is 9 volts and the resistance is 4 ohms.
a. 36 amps
b. 2.25 amps
c. 2 amps
d. 18 amps
2. Find the current in a circuit where the voltage is 120 volts and the resistance is 4 ohms.
a. 3 amps
b. 240 amps
c. 30 amps
d. 480 amps
3. Find the voltage in a circuit where the current is 10 amps and the resistance is 12 ohms.
a. 1.2 volts
b. 60 volts
c. 0.83 volts
d. 120 volts
4. Find the voltage in a circuit where the current is 3 amps and the resistance is 3 ohms.
a. 1 volt
b. 9 volts
c. 0 volts
d. 120 volts
5. Find the resistance in a circuit where the current is 10 amps and the voltage is 120 volts.
a. 130 ohms
b. 1200 ohms
c. 12 ohms
d. 110 ohms
6. Find the resistance in a circuit where the current is 20 amps and the voltage is 120 volts.
a. 6 ohms
b. 12 ohms
c. 240 ohms
d. 100 ohms
Suppose the velocity of a car at any time t is given by the equation
v=60 m/s +0.50 m/s³h,
Derive an expression for the instantaneous acceleration as a function of time
Answer: acceleration is time derivative of speed.
When v(t) = 60 + 0.50t, is a(t) = v' (t) = 0.50 (m/s²)
I need help so bad pls pls help
Answer:
I think it is protection
Answer:
I think it might be PROTECTION but i not sure for a fact
Sorry if i get it wrong ;]
Explanation:
Light waves Group of answer choices are not electromagnetic radiation. do not require a medium. can not travel in a vacuum. do not travel in straight lines from the source.
Answer:
do not require a medium
Explanation:
Light waves can be regarded as electromagnetic waves and it transverse in nature, no medium material is required to pass through. Light wave can travel through vacuum and it's ray can travel in straight lines even from point source. Light convey energy in perpendicular direction to electric field as well as magnetic field.
The ratio of the speed of light in a medium to the speed of light in a vacuum
is called its:
A. angle of incidence
B. Snell's Law
C. angle of refraction
D. refractive index
Answer:D.Refractive Indez
Explanation:
It is usually expressed the other way: the ratio of the speed of light in a vacuum to the speed of light in a medium. In that case, it is called the "index of refraction".
You're going for "refractive index", but you've got the ratio flipped over.
a car weighs 2000 kg if it is moving at a speed of 15 m/s what’s the linear momentum of the car?
Answer: 40,000kg m/s option c)
Explanation:
Given data
m1= 2000kg
u1= 20m/s
m2= 1500kg
u2= 0m/s
v1= 10m/s
Required
The speed of the sticks
We know that from the expression for the conservation of momentum
m1u1+m2u2= m1v1+m2v2
2000*20+1500*0=2000*10+1500*v2
40000=20000+1500v2
collect like terms
40000-20000= 1500v2
20000= 1500v2
v2= 20000/1500
v2= 13.33 m/s
Hence the velocity of the sticks is 40,000kg m/s
I hope I helped!! ❤️
Calculate the first and second velocities of the car with three washers attached to the pulley, using the formulas
v1 = 0.25 m / t1, and
v2 = 0.25 m / (t2 – t1)
where t1 and t2 are the average times the car took to reach the 0.25 and the 0.50 meter marks. Record these velocities, to two decimal places, in Table E.
What is the first velocity of the car with three washers at the 0.25 meter mark?
m/s
What is the second velocity of the car with three washers at the 0.50 meter mark?
m/s
Answer:
0.19 and 0.45
Explanation:
edge
The first and second velocities of the car are [tex]0.25/t_1[/tex] and [tex]0.50/t_2[/tex]respectively.
What is velocity?The velocity of an object is defined as the product of the distance travelled in a given direction and the time required to travel that distance. The velocity is expressed mathematically as,
v = d/t
Here, d represents the travelled distance.
And t is the typical amount of time needed to go the distance.
Given,
The value of the first distance is, d1 = 0.25 m.
The value of the second distance is, d2 = 0.50 m.
Then the first velocity of the car at 0.25 m is,
[tex]v_1 = d_1/t_1\\v_1 = 0.25 / t_1[/tex]
Thus,[tex]t_1[/tex] denotes the first distance's typical time.
The second velocity of the car with three washers at the 0. 50 m mark is
[tex]v_2 = d_2/t_2\\v_2 = 0.50 /t_2[/tex]
Here, [tex]t_2[/tex] stands for the second distance's typical time.
Thus, the first and second velocities of the car are [tex]0.25/t_1[/tex] and [tex]0.50/t_2[/tex]respectively.
Learn more about Velocity, here:
brainly.com/question/25796948
#SPJ2
A runner of 60kg accelerates at 2.0 m/s at the start of race calculate the force provided from her legs
Answer:
120 kgm/s
Explanation:
Force= mass× acceleration
= 60kg × 2.0m/s
= 120 kgm/s
does frequency of the sound affect speed of sound
Answer:
One of the more important properties of sound is that its speed is nearly independent of frequency. ... Therefore, the relationship between f and λ is inverse: The higher the frequency, the shorter the wavelength of a sound wave. The speed of sound can change when sound travels from one medium to another.
what is the magnitude of vector A?
please tell what is energy
Answer:
the capacity to do work is called energy