The earplug can reduce the sound level to about 18 decibels (dB). What percentage reduction is this intensity?

Answers

Answer 1

Answer:

1 x 10 -10 whisper at 1m distance.

Explanation:

Properly fitted ear plugs an reduce noise form 15-30db. Although they are better for low frequency
Answer 2

Answer:

The change in intensity is 63%.

Explanation:

intensity level = 18 db

Let the intensity is I.

Io = 10^(-12) W/m^2

Use the formula of intensity

[tex]dB = 10 log\left ( \frac{I}{Io} \right )\\\\18 = 10 log\left ( \frac{I}{Io} \right )\\\\1.8 = log\left ( \frac{I}{Io} \right )\\\\\left ( \frac{I}{Io} \right )=63.1[/tex]

So, the change in intensity is 63%.


Related Questions

What are three differences and similarities between a Vernier Calipers and a Micrometer? (please leave a good answer)

Answers

Answer:

Explanation:

Vernier scale

Mathematical tool

A vernier scale, named after Pierre Vernier, is a visual aid to take an accurate measurement reading between two graduation markings on a linear scale by using mechanical interpolation; thereby increasing resolution and reducing measurement uncertainty by using vernier acuity to reduce human estimation error. Wikipedia

Purpose: Measuring more precisely than could be done unaided when reading a uniformly divided straight or circular measurement scale

Creator: Pierre Vernier

Year invented: 1631

..............................................................................................................................................................................................................................................................................................

A micrometer is a measuring instrument that can make extraordinarily precise measurements. Most micrometers are designed to measure within one one-thousandth of an inch! That's a close fit. Exact measurements like this are necessary when even the smallest of space between objects can cause problems or difficulties.

Micrometer

Mathematical tool

A micrometer, sometimes known as a micrometer screw gauge, is a device incorporating a calibrated screw widely used for accurate measurement of components in mechanical engineering and machining as well as most mechanical trades, along with other metrological instruments such as dial, vernier, and digital calipers. Wikipedia

Operation supported: Component measurement

Purpose: Precision measurement of a component

Variant: Digital mics, Bench micrometer, Limit mics, Digit mics, MORE

Component: Screw, Spindle, Ratchet stop, Anvil, Frame, Barrel, Thimble lock, Thimble

Application: Mechanical Engineering, Machining

state the term used to describe the turning force exerted by the man pushing down on a lever to lift one end of a heavy log​

Answers

A force called the effort force is applied at one point on the lever in order to move an object, known as the resistance force, located at some other point on the lever.

The way levers work is by multiplying the effort exerted by the user. Specifically, to lift and balance an object, the effort force the user applies multiplied by its distance to the fulcrum must equal the load force multiplied by its distance to the fulcrum. Consequently, the greater the distance between the effort force and the fulcrum, the heavier a load can be lifted with the same effort force.

The term used to describe the turning force exerted when pushing an object is effort.

What is effort?

The is the input force or force applied at one point of a lever in order to overcome a load.

The relationship between effort, load and mechanical advantage of a lever is given as;

M.A = L/E

where;

M.A is mechanical advantageL is the loadE is the applied force or effort

Thus, the term used to describe the turning force exerted when pushing an object is effort.

Learn more about effort here: https://brainly.com/question/24237657

a load of 800 newton is lifted by an effort of 200 Newton. if the load is placed at a distance of 10 cm from the fulcrum. what will be the effort distance ?​

Answers

Answer:

40 cm

Explanation:

We are given that

Load=800 N

Effort=200 N

Load  distance=10 cm

We have to find the effort distance.

We know that

[tex]load\times load\;distance=Effort\times effort\;distance[/tex]

Using the formula

[tex]800\times 10=200\times effort\;distance[/tex]

Effort distance=[tex]\frac{800\times 10}{200}[/tex]

Effort distance=[tex]\frac{8000}{200}[/tex]

Effort distance=40 cm

Hence,  the effort distance will be 40 cm.

The distance a cart moves down a track (from rest) is proportional to the time squared. How far would a cart move down a track (from rest) in two seconds if it moves (from rest) a distance of 20 cm in one second?

A) 5 cm B) 10 cm C) 20 cm D) 40 cm E) 80 cm

Answers

A car move down a track a distance of 80 cm

Letter E  80 cm

Proportional

if the distance is proportional to the time square we can express such condition writing

d = k*t²        (1)

where d is the distance t is the time and k is the constant of proportionality.

Now we must considerer that if the cart moves a distance of 20 cm in one second then by substitution in equation (1)

20 = k * (t)²        ⇒     20 = k*1   then   k = 20

The proportionality constant is K = 20

To determine how far the cart move down in 2 seconds, again by substitution in equation (1) ( but now knowing k )

d = 20*(2)²

d = 20*4

d = 80 cm

Guys please help this is very important it would be greatly appreciated if you would add the work. Thank you !!

Answers

Answer:

enjoy

Explanation:

The number of time a cricket chirps in a minute is a function of the temperature in the formula: n=4t-160, where n=number of times a cricket chirps a minute and t=temperature in farenheit. You can use the temperature t=(1/4)n+40 to estimate the temperature based on the number of chirps per minute.

John walked a distance of 900 meters in 10 minutes what was his average speed in kilomerters per hour

Answers

Answer:

5.4

Explanation:

900/10=90 and 90(60)=5400 meters. 5400/100=5.4

A ball of mass 1.0 kg is rolling due west at 30 m/s. A second ball of mass 2.0 kg moving due north at 6.0 m/s collides with the first ball and they stick together. What is the magnitude of the momentum of the two-ball system immediately after collision

Answers

Answer:

the magnitude of the momentum of the two-ball system immediately after collision is 32.31 kg.m/s

Explanation:

Given;

mass of the first ball, m₁ = 1.0 kg

mass of the second ball, m₂ = 2.0 kg

initial velocity of the first ball, v₁ = 30 m/s due west

initial velocity of the second ball, v₂ = 6 m/s due north

From the principle of conservation of linear momentum;

the total momentum before collision = total momentum after collision

The westward momentum of the first ball, = m₁v₁ = 1 x 30 = 30 kg.m/s

The northward momentum of the second ball = m₂v₂ = 2 x 6 = 12 kg.m/s

The resultant momentum of the two balls;

R² = 30² + 12²

R² = 1044

R = √1044

R = 32.31 kg.m/s

Therefore, the magnitude of the momentum of the two-ball system immediately after collision is 32.31 kg.m/s

y’all know what to do… please help

Answers

Answer:

A. It increased gradually as the reaction progressed.

Answer: A it increased gradually

as the reaction progressed

Lifestyle practice that can improve your quality of life

Answers

Explanation:

And keep changing gradually.

Eat a variety of foods. ...

Base your diet on plenty of foods rich in carbohydrates. ...

Replace saturated with unsaturated fat. ...

Enjoy plenty of fruits and vegetables. ...

Reduce salt and sugar intake. ...

Eat regularly, control the portion size. ...

Drink plenty of fluids. ...

Maintain a healthy body weight

A 5.41 kg ball is attached to the top of a vertical pole with a 2.37 m length of massless string. The ball is struck, causing it to revolve around the pole at a speed of 4.75 m/s in a horizontal circle with the string remaining taut. Calculate the angle θ, between 0∘ and 90∘, that the string makes with the pole. Use g=9.81 m/s2.

Answers

Answer:

θ = 66º

Explanation:

This exercise of Newton's second law must be solved in part, let's start by finding the slowing down acceleration of the ball

           a = v² / r

the radius of the circle is

          sin θ = r / L

          r = L sin θ

           

we substitute

          a = v² /L sin θ

now let's write Newton's second law

vertical axis

            T_y -W = 0

             T_y = W

radial axis

            Tₓ = m a                 (1)

let's use trigonometry for the components of the string tension

             cos θ = T_y / T

             sin θ = Tₓ / T

             Tₓ = T sin θ

we substitute in 1

            T sin θ = [tex]\frac{m \ v^2}{L \ sin \theta}[/tex]

             T L sin² θ = m v²

we write our system of equations

             T cos θ  = m g

             T L sin ² tea = m v²

we divide the two equations

             L [tex]\frac{sin^2 \theta}{cos \theta}[/tex] = v² / g

             (1 -cos²)/ cos θ  = [tex]\frac{v^2 }{g \ L}[/tex]

             1 - cos² θ  =  [tex]\frac{4.75^2}{9.81 \ 2.37}[/tex]   cos θ

             cos² θ + 0.97044 cos θ -1   = 0

we change variable    cos  θ = x

             x² + 0.97044 x - 1 =0

             x= [tex]\frac{-0.97 \pm \sqrt{0.97^2 - 4 1} }{2}[/tex]

           since the square root is imaginary there is no real solution to the problem, suppose that the radius is 1 m r = 1 m

           T sin θ = [tex]\frac{m \ v^2}{ r}[/tex]

           T cos θ  = m g

resolved

           tan θ =  [tex]\frac{v^2}{ r g}[/tex]

           θ = tan⁻¹ ( 4.75²/ 1 9.81)

           θ = 66º

The pressure at the ice point for a constant-volume gas thermometer is 4.81 x 10^4Pa.
While that at the steam point is 6.48 x 10^4 Pa.
What pressure would the thermometer indicate at 50°c?

Answers

Answer:

0 deg C = 4.81E4     pressure at 0 deg

100 deg C = 6.48E4     pressure at steam point

100 deg C - 50 deg C = (6.48 - 4.81) * 10^4 = 1.67E4 Pa

50 deg C = 50 / 100 * 1.67E4 + 4.81E4 = 5.65E4 Pa Just the halfway point between the two given pressures

can anyone please help me​

Answers

Answer:its most likely c

Explanation:

the unit of force and pressure are called derived unit​

Answers

Answer:

yes

Explanation:

because they can be derived in the form of base units

If the half-life of a decaying isotope is 10 years, which statement is true after
10 years?

Answers

Answer:

no is the most expensive but u have

Difference between gravitational force and frictional​

Answers

Explanation:

gravitational force or gravity is the force of attraction between objects that have mass.

frictional force is the forec that opposes motion (movement) when two surface are in contact. (acts in the opposite direction of motion)

so to sum it up,

- gravtional force is the force of attraction between objects that have mass.

- objects on the earth have weight because of gravitational force between them and the earth.

frictional force

- oppose motion

- slow down and stop moving objects and;

- produce heat

hope it helps :)

Answer: the difference is that they are 2 completely separate things

explain how force and surface area affect the applied pressure.​

Answers

Answer:

force and surface area are two factors affecting pressure on solids

more the force you apply, more will be the pressure

pressure and force are directly proportional meaning if Force is greater, pressure will also be greater

more the surface area of the solid less will be the pressure

surface area and pressure are inversely proportional meaning if surface are is big, pressure will be less, surface area small, pressure will be greater

Answer and Explanation:

We have a basic equation: Pressure = Force/Area.

So for example:

Increase pressure - increase the force or reduce the area the force acts on.

Decrease pressure - decrease the force, or increase the area the force acts on

The force per unit area is pressure. The force on the object is spread over the surface area. The area where the force is applied is divided by the equation for pressure.

Cheers,

Un auto se desplaza por una carretera recta a una velocidad de 85 km/h. Al cabo de 2 horas, ¿qué distancia habrá recorrido, en metros?

Answers

Answer:

Distancia, D = 170,000 metros

Explanation:

Dados los siguientes datos;

Velocidad = 85 km/h Tiempo = 2 horas

Para encontrar la distancia recorrida, en metros;

Matemáticamente, la distancia recorrida por un objeto se calcula mediante la fórmula;

Distancia = velocidad * tiempo

Sustituyendo los valores en la fórmula, tenemos;

Distancia = 85 * 2

Distancia = 170 kilómetros

A continuación, convertiríamos el valor en kilómetros a metros;

Conversión:

1 kilómetros = 1000 metros

170 kilómetros = D metros

Multiplicación cruzada, tenemos;

D = 170 * 1000

D = 170,000 metros

Por lo tanto, habría viajado 170,000 metros después de 2 horas.

How can you say gravitational force is a field force

Answers

Answer:

because gravity pulled us in the land if there is no gravitational force there will not be field force too

Explanation:

hope it's will help you

Which are characteristics of a prokaryotic cell? Select three options.


O contains DNA

O lacks DNA

O contains ribosomes

O lacks ribosomes

O contains a nucleus

O lacks a nucleus

I NEED THIS QUICKLY

Answers

Answer:

A. Contains DNA

C. Contains ribosomes

F. Lacks a nucleus

Explanation:

A skipper on a boat notices wave crests passing his anchor chain every 5.6 s . He estimates the distance between wave crests to be 16 m . He also correctly estimates the speed of the waves. Find this speed.

Answers

Answer:

v = 2.85 m/s

Explanation:

Given that,

A skipper on a boat notices wave crests passing his anchor chain every 5.6 s.

The distance between wave crests to be 16 m.

We need to find the speed of the waves. The speed of a wave can be calculated by the formula as follows :

[tex]v=f\lambda\\\\v=\dfrac{\lambda}{T}\\\\v=\dfrac{16}{5.6}\\\\v=2.85\ m/s[/tex]

So, the speed of the wave is 2.85 m/s.

Which nucleus completes the following equation?
Please ignore the answer I chose, it might be wrong

Answers

Answer:

D. [tex]^{39}_{18} Ar[/tex]

Explanation:

The given nuclear equation is the beta decay of chorine in which an electron, known as a beta particle, is given off from within the nucleus due to the breakdown of a neutron within the nucleus into a proton and a beta particle, such that the atomic number is increased by 1 from 17 to 18, which is the atomic number or argon, Ar, as follows;

[tex]^{39}_{17}Cl \ \rightarrow \ ^0_{-1} e + \ ^{39}_{18} Ar[/tex]

you now barbecue is hot, but have you ever thought about the methods of heat transfer related to barbecue?
a) at your barbecue party, what would be an example of heat by conduction?
b) at your barbecue party where would heat be transferred b convection?
c) there is also radiation from the barbecue. where would you best feel this?
d) in some grill oven you put your meat under the heating element your meat is grilled by the heat coming from above. it will take longer to cook this meat than a similar piece on the barbecue can you explain this?

Answers

Answer:

Explanation:

There are three modes of heat transfer.

1. Conduction: It is the mode of heat transfer when the object is in contact with hot body and gradually the heat transfer from the hot end to the cold end.

2. Convection: It is the mode of heat transfer in which the molecules gets heated and moves up and the cold molecules comes down and the process continues till the entire liquid or gas is at same temperature.

3. Radiation: It is the process of heat transfer in which the heat is transferred in the form of heat waves.

(a) When the cook pot is placed on flame, it is the example of conduction.

(b) When the liquid is placed on the flame in a container, the liquid gets heated by the mode of convection.  

(c) We feel heat as we stand near the flame so it is the example of radiation.

(d) because the heat is trapped so it becomes hot in lesser time.

Can acceleration and velocity be equal vectors?

Answers

Answer:

Velocity is the rate of change of position with respect to time, whereas acceleration is the rate of change of velocity. Both are vector quantities (and so also have a specified direction), but the units of velocity are meters per second while the units of acceleration are meters per second squared.

Reference frame definitely changes when also changes

Answers

Reference frame definitely changes when the body is changing. That is the reason that in order to describe the position of a point that moves relative to a body that is moving relative to the Earth, it is usually convenient to use a reference frame attached to the moving body.

After release of jet, energy is lost by the engine. How principle of conservation of energy is obeyed in this condition.​

Answers

Answer:

The principle of conservation of energy states that in a closed system, the energy can neither be created nor destroyed between interacting particles and remains constant or transformed from one form to another

In the jet engine, the release of jet changes the number of interacting particles in the engine, and given that energy cannot be created in the instantaneously closed system of the engine, energy is carried away and therefore lost by particles in the jet exhaust

The conservation of energy principle is therefore obeyed in the condition in which the jet engine losses energy by the release of jet

Explanation:

1.Convert 340 cm into m *(answer=0.34m)

2.What is the weight of potatoes of mass 75kg on the surface of the earth? *(ans=735 N)

[g=9.8 m/s^2

[g=9.8 m/s^2]

3.The weight of body is 420 N.Calculate its mass. *(42.857 kg)*


Answers are all given so i just need the process please (i will mark you brainliest please..

Answers

Answer:

1.for the first one 100centimeters make 1 meter therefore

100cm-1m

340cm-x

340/100

=3.4

the answer is supposed to be 3.4, maybe there's a mistake with the question or the answer

2.the weight of a body is given by the formula

mass×gravity,in this case the mass is 75kg and the gravity is 9.8

weight=75×9.8

=735N

3.for this one the mass of a body is given by the formula

mass=weight/gravity

=420/9.8

=42.8kg

I hope this helps

An iron weight, suspended by a string, is motionless. The tension
in the string is 4.75 newtons. What is the mass of the iron
weight?

Answers

Answer:

Explanation:

If the mass hangs at the end of the string and the string can support the mass and doesn't break, and the mass hangs still, that means that the tension in the string is equal to the downward pull of the mass. However, we are given the tension in Newtons and the mass needs to be in kg. So we use the equation for weight:

w = mg where w, the weight, is the same as the tension in the string. Gravity is always 9.8 in the metric system:

4.75 = m(9.8) so

m = .48 kg

Answer:

Answer: A

0.485 Kg

Explanation:

which of the following containing same amount of boiling hot water is likely to cool first and why? a. a breaker whose surface is covered with aluminum foil b. a breaker whose surface is painted black​

Answers

B. A beaker whose is surface is painted black

Which of the elements below have seven electrons in their outermost energy levels? A.) Cr, Mn, and Fe B.) Br, I, and Ci C.) O, S, and Se D.) He, Ne, and Ar

Answers

Answer:

B

Explanation:

the Halogen families have 7 valence electrons

Does water exist on Mars? Explain your answer. Why didn't Jupiter become a star during the early.​

Answers

Answer:

yes water was discovered in mars

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