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PSYCHO15rus [73]
4 years ago
7

A sound system is designed to produce a 1.0W/m2 sound intensity over the surface of a hemisphere 20 m in radius. What acoustic p

ower is needed from an array of speakers at the center of the sphere?
Physics
1 answer:
Marina CMI [18]4 years ago
3 0

Answer:

2513.6 W

Explanation:

Acoustic power = sound intensity × area of hemisphere

Sound intensity = 1 W/m^2

Area of hemisphere = 2πr^2 = 2×3.142×20^2 = 2513.6 m^2

Acoustic power = 1 W/m^2 × 2513.6 m^2 = 2513.6 W

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What happens when the density of a medium increases
Anvisha [2.4K]
We all know that the sound travels faster through solids and then liquids and then through gases.
As far as i know solids are the medium through which the sound travels fast.

But in some websites I saw that as the density increases , the velocity of the sound decreases.If this statement is correct , how come the sound travels fastest through solids (since they have higher density) 

From this it is clear that not only sound as compression wave But also in the form of Shear wave travels in Solids

This makes it easier for sound to travel with higher speed in solids
8 0
3 years ago
Read 2 more answers
Explain in terms of energy how dissipative forces such as friction reduce the amplitude of a harmonic oscillator. Also explain h
miss Akunina [59]

Answer:

There is the conservation of energy in a harmonic oscillator. As a result, the system amplitude will remain constant. The dissipative forces (i.e. friction) lead to loss of energy in different forms and the system amplitude is reduced due to the reduction in both kinetic and potential energies at the end of each oscillation.

The external forces acting on a driving mechanism must be accounted for at all times. In this case, there is a loss of energy because dissipative forces can be returned back to the system in the presence of the driving to account for the loss in energy.

Explanation:

There is the conservation of energy in a harmonic oscillator. As a result, the system amplitude will remain constant. The dissipative forces (i.e. friction) lead to loss of energy in different forms and the system amplitude is reduced due to the reduction in both kinetic and potential energies at the end of each oscillation.

The external forces acting on a driving mechanism must be accounted for at all times. In this case, there is a loss of energy because dissipative forces can be returned back to the system in the presence of the driving to account for the loss in energy.

5 0
3 years ago
Read 2 more answers
Which was NOT a feature of welfare reform
qaws [65]
HeLLo tHeRe!

Your answer should be public transportation vouchers

Hope this helps. 
Have a nice day.


8 0
4 years ago
The automobile has a weight of 2700 lb and is traveling forward at 4 ft>s when it crashes into the wall. If the impact occurs
alex41 [277]

Answer:

F_b=153918\, lb.ft.s^{-2}

Explanation:

Given:

mass, m=2700 \,lb

time, t=0.06\,s

velocity, v=4\,ft.s^{-1}

coefficient of kinetic friction between wheels & pavement, \mu=0.3

According to first condition,

F\times \Delta t=m\times v

F\times 0.06= 2700\times 4

F=180000\,lb.ft.s^{-2}

According to second condition,

<u>Magnitude of frictional force (which acts opposite to the direction of motion):</u>

f=\mu.N

where N is the normal reaction.

f=0.3\times 2700\times 32.2

f=26082 \,lb.ft.s^{-2}

Now, the impulsive force on the wall if the brakes were applied during the crash:

F_b= F-f

F_b=180000-26082

F_b=153918\, lb.ft.s^{-2}

3 0
3 years ago
A car, moving along a straight stretch of highway,
yarga [219]
<span>We know that an object in moving with acceleration follow the rule according that the distance covered will be : d = Vi*t + 1/2*a*t^2 where d is distance, Vi is initial speed, and a is acceleration Then after 1 km which is 1000 metres we have: 1000 = Vi *71.2 + 1/2*0.0499*(71.2)^2 Vi = (1000-1/2*0.0499*(71.2)^2)/71.2 = 1000/71.2 - 1/2*0.0499*71.2 = 12.27 m/s Then the car was going at 12.27 m/s when started to accelerate.</span>
5 0
4 years ago
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