For a simple harmonic motion energy is given with:

Where k is a constant that depends on the type of the wave you are looking at and A is amplitude.
Let's calculate the energy of the wave using two different amplitudes given in the problem:

We can see that energy associated with the wave is 4 times smaller when we decrease its amplitude by half. So the answer should be C.
Answer:
A) Propagation of pressure fluctuations in a medium
B) air is the medium in which the wave is transported,
Explanation:
Part A.
A sound wave is a longitudinal oscillation of the molecules that forms in a material medium, they can be solid, liquid or gases, therefore the wave propagates in the same direction as the oscillation of the particles.
The most correct answer is:
* Propagation of pressure fluctuations in a medium
Part b
air is the medium in which the wave is transported, otherwise it cannot propagate
Answer:
4A
Explanation:
According to ohm's law;
E = IRt where;
E is the source voltage = 24volts
I is the total current flowing in the circuit = ?
Rt is the total effective resistance in the circuit.
To find Rt, we will resolve the resistors in parallel first.
Since 6ohms and 12ohms resistors are in parallel, their effective resistance will give;
1/R = 1/6+1/12
1/R= 2+1/12
1/R = 3/12
3R = 12
R = 4ohms.
This resistor will now be in series with the 2.0ohms resistor to finally have;
Rt = 4+2
Rt = 6ohms
From the ohms law formula;
I = E/Rt
I = 24/6
I = 4Amperes
The total current in the circuit is 4A
This same currents will flow in the 2ohms resistor since same current flows in a series connected resistors.
Explanation :
A power amplifier is used to amplify electric signals i.e. to increase the low power signal to higher powers.
A PNP transistor is connected in a circuit so that the collector-base junction remains reverse biased and the emitter-base junction is forward biased.
This transistor can be used as a power amplifier because it gives a much larger output current. The gain of an amplifier shows the amount of amplification. It is the difference between the input and the output signals.
Answer:
16.7 s
Explanation:
T= <u>Vf - Vo</u> a= <u>F</u>
a m
4,500 / 3000 = 1.5 (a)
30 - 5 / 1.5(a) = 16.7 s