Answer:
iv) It is 9x bigger than before
Explanation:
As the amplitudes of the new speakers add directly with the original one, taking into account the phase that they have, the composed amplitude of the sound wave is as follows:
At = A + 4A -2A = 3 A
The intensity of the wave, assuming it propagates evenly in all directions, is constant at a given distance from the source, and can be expressed as follows:
I = P/A
where P= Power of the wave source, A= Area (for a point source, is equal to the surface area of a sphere of radius r, where is r is the distance to the source along a straight line)
For a sinusoidal wave, the power is proportional to the square of the amplitude, so the intensity is proportional to the square of the amplitude also.
If the amplitude changes increasing three times, the change in intensity will be proportional to the square of the change in amplitude, i.e., it will be 9 times bigger.
So, the statement iv) is the right one.
Alright well the Answer to your question is A). Screw
Hope this helps have a nice day : )
If u want i can explain why
Answer:
1.92 kg of nitrogen.
Explanation:
The following data were obtained from the question:
Heat absorbed (Q) = 384000 J
Note: Heat of vaporisation (ΔHv) of nitrogen = 5600 J/mol
Next, we shall determine the number of mole of nitrogen that absorbed 384000 J.
This is illustrated below:
Q = mol·ΔHv
384000 = mole of N2 x 5600
Divide both side by 5600
Mole of N2 = 384000/5600
Mole of N2 = 68.57 moles
Next, we shall convert 68.57 moles of nitrogen, N2 to grams.
This can be obtained as follow:
Molar mass of N2 = 2 x 14 = 28 g/mol.
Mole of N2 = 68.57 moles.
Mass of N2 =..?
Mole = mass /molar mass
68.57 = mass of N2 /28
Cross multiply
Mass of N2 = 68.57 x 28
Mass of N2 = 1919.96 g
Finally, we shall convert 1919.96 g to kilograms.
This can be achieved as shown below:
1000g = 1 kg
Therefore,
1919.96 g = 1919.96/1000 = 1.92 kg.
Therefore, 1.92 kg of nitrogen were burned off.
C) alternately increase and decrease
The work-energy principle states that the work done by all the non-conservative forces acting on an object (or system of objects) causes a change in the total mechanical energy of the object or system.
What is the work-energy principle?
The work-energy principle states that the total work done on a system is equal to the change in kinetic energy of the system. It is given as:
W.D = ΔK.E
= K.E₁ - K.E₂
where K.E₁ is the initial kinetic energy of the system
K.E₂ is the final kinetic energy of the system
What is meant by non-conservative forces?
Non-conservative forces as the name suggests are not conserved i.e. these forces cause a loss of mechanical energy from the system. A prime example of non-conservative forces is friction.
The total mechanical energy of the system is the sum of the potential energy and kinetic energy that the system contains. This energy is conserved and follows the work-energy theorem.
Learn more about work and energy here:
<u>brainly.com/question/17290830</u>
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