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3 years ago

By what factor must the sound intensity be increased to increase the sound intensity level by 12.5 db ?

1 answer:

8 0

The sound has a unit of measurement. In physics, there are two measurements: in intensity (Watts per square meterI or in decibels. The most common unit of measurement is in decibels or dB. In fact, the threshold of hearing when it comes to measuring noise is in terms of decibels.

To convert decibels to intensity in W/^2, the equation is

dB = 10log(I/I0), where I0 is equal to 10^-16. It is an empirical constant for the standard reference intensity. Therefore,

12.5 = 10 log (I/10^-16)
I = 1.78 × 10^-15 W/m^2

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Conditions of equilibrium of parallel coplanar forces<br><br><br>

IRISSAK [1]

Answer:

Bruh............

Explanation:

8 0

3 years ago

Use the diagram below to answer the following question:

d1i1m1o1n [39]

Answer:

3.0 cm

Explanation:

We can solve this problem by using the mirror equation:

$\frac{1}{f}=\frac{1}{p}+\frac{1}{q}$

where

f is the focal length of the mirror

p is the distance of the object from the mirror

q is the distance of the image from the mirror

In this problem we have:

f = 1.5 cm is the focal length of the mirror (positive for a concave mirror)

p = 3.0 cm is the distance of the object from the mirror

Therefore, the distance of the image is:

$\frac{1}{q}=\frac{1}{f}-\frac{1}{p}=\frac{1}{1.5}-\frac{1}{3.0}=\frac{1}{3.0}\\\rightarrow q=3.0 cm$

And the positive sign means that the image is real.

(The second part of the exercise is just the description of the image of the first exercise).

5 0

2 years ago

A box slides down a ramp inclined at 24◦ to the horizontal with an acceleration of 1.7 m/s 2 . The acceleration of gravity is 9.

dsp73

Answer:

Explanation:

In friction, the coefficient of friction formula is expressed as;

$\mu = \frac{F_f}{R}$

Ff is the frictional force = Wsinθ

R is the reaction = Wcosθ

Substitute inti the equation;

$\mu = \frac{Wsin \theta}{W cos\theta} \\\mu = \frac{sin \theta}{cos\theta} \\\mu = tan \theta$

Given

θ = 24°

$\mu = tan 24^0\\\mu = 0.445\\$

Hence the coefficient of kinetic friction between the box and the ramp is 0.445

3 0

3 years ago

A beam of protons is directed in a straight line along the +z direction through a region of space in which there are crossed ele

IceJOKER [234]

Answer:

B = 7.6 T direction of + x

Explanation:

For the proton beam to continue in the same direction the electric and magnetic forces must be equal

$F_{m} - F_{e}$ = 0

$F_{m}$ = F_{e}

Fm = q E

The electric force is in the direction of the electric field because it is the charge of the positive proton, the electric force goes in the direction of –y, therefore, the magnetic force cancels this force must go in the direction of + y

The magnetic force is

F_{m} = q v x B = q v B sin θ

θ = 90

B = q E / q v

B = E / v

B = 800/105

B = 7.6 T

To find the direction of the magnetic field we use the right hand rule, the thumb goes in the direction of the proton velocity, the fingers extended in the direction of the magnetic field and the palm is the direction of force, for a positive charge.

Thumb goes in the direction of the + z axis

Palm in the direction of +y

Fingers point in the direction of + x

7 0

2 years ago

A fisherman notices that his boat is moving up and down periodically, owing to waves on the surface of the water. It takes 2.5 s

gulaghasi [49]

(a) 0.96 m/s

The period of the wave corresponds to the time taken for one complete oscillation of the boat, from the highest point to the highest point again. Since the time between the highest point and the lowest point is 2.5 s, the period is twice this time:

$T=2\cdot 2.5 s=5.0 s$

The frequency of the waves is the reciprocal of the period:

$f=\frac{1}{T}=\frac{1}{5.0 s}=0.20 Hz$

The wavelength instead is just the distance between two consecutive crests, so

$\lambda=4.8 m$

And the wave speed is given by:

$v=\lambda f=(4.8 m)(0.20 Hz)=0.96 m/s$

(b) 0.265 m

The total distance between the highest point of the wave and its lowest point is

d = 0.53 m

The amplitude is just the maximum displacement of the wave from the equilibrium position, so it is equal to half of this distance. So, the amplitude is

$A=\frac{d}{2}=\frac{0.53 m}{2}=0.265 m$

(c) Amplitude: 0.15 m, wave speed: same as before

In this case, the amplitude of the wave would be lower. In fact,

d = 0.30 m

So the amplitude would be

$A=\frac{d}{2}=\frac{0.30 m}{2}=0.15 m$

Instead, the wave speed would not change, since neither the frequency nor the wavelength of the wave have changed.

8 0

3 years ago