According to Boyle’s law, For a fixed amount of an ideal gas kept at a fixed temperature, P (pressure) and V (volume) are inversely proportional.
Therefore,

Given  ,
 ,  and
 and  .
.
Thus,

 
        
             
        
        
        
Answer:
Decreases by  times
 times
Explanation:
The intensity of a sound is defined as the energy of the sound that is flowing in an unit time through the unit area which is in the direction that is perpendicular to the direction of the sound waves movement. 
The intensity of energy is described by the inverse square law. It states that the intensity varies inversely with the distance square of the distance. 
In other words, the sound intensity decreases as inversely proportional to the squared of the distance.  i.e. 
In the context when the distance was 3 m, the intensity of the sound was = 
But when the distance became 6 cm or 0.06 m, the sound intensity decreases by =  
                        =  times
 times
 
        
             
        
        
        
Answer:
The angle between the electric field and the axis of the filter is 54⁰
Explanation:
Apply the equation for intensity of light through a polarizer.

where;
I is the intensity of the transmitted light
I₀ is the intensity of the incident light
θ is the incident angle
If only 35 % of the intensity of a polarized light wave passes through a polarizing filter, then the ratio of the intensity of the transmitted light to that of the intensity of the incident light is given by;

Therefore, the angle between the electric field and the axis of the filter is 54⁰
 
        
             
        
        
        
Answer:
a) and c).
Explanation:
For a complete destructive interference occur, it must be met the following condition relating the wavelength, and the difference in the paths taken by the sound emitted by the sources until arriving to the listening point:
d = |dA- dB| = (2n-1)*(λ/2)
For n= 1,  d = λ/2 = 0.25 m, it doesn't meet any of the cases.
For n=2, d= 3*(λ/2) = 0.75 m
In the case a) we have dA = 2.15 m and dB = 3.00 m, so dB-dA = 0.75 m, which means that in the location stated by case a) a complete destructive interference would occur.
For n=3, d= 5*(λ/2) = 5*0.25 m = 1.25 m.
This is just the case c) because we have dA = 3.75 m and dB = 2.50 m, so dA-dB = 1.25 m, which means that in the location stated by case c) a complete destructive interference would occur also.
The remaining cases don't meet the condition stated above, so the statements found to be true are a) and c),