Answer:
The film thickness is 4.32 * 10^-6 m
Explanation:
Here in this question, we are interested in calculating the thickness of the film.
Mathematically;
The number of fringes shifted when we insert a film of refractive index n and thickness L in the Michelson Interferometer is given as;
ΔN = (2L/λ) (n-1)
where λ is the wavelength of the light used 
Let’s make L the subject of the formula 
(λ * ΔN)/2(n-1) = L
From the question ΔN = 8 , λ = 540 nm, n = 1.5 
Plugging these values, we have 
L = ((540 * 10^-9 * 8)/2(1.5-1) = (4320 * 10^-9)/1 = 4.32 * 10^-6 m 
 
        
             
        
        
        
Density = mass / volume ;
1 Cubic Centimeter = 0,000001 Cubic Meter
8 cm^3 = 0.000008 m^3
12,9 g = 0,0129 kg
The density is 0,0129 kg/ 0,000008 m^3 = <span><u>1612,5 kg/m^3</u> </span>
        
             
        
        
        
Hello there.
<span>Which acid will undergo 100% dissociation when dissolved in water?
Answer:</span><span> HCL
</span><span>
Option: C
Second Question...not sure.
</span>
        
                    
             
        
        
        
Answer:
5880lb-ft of work is done
Explanation:
The length of the heavy rope is given as 60ft and the weight per length is 0.7lb/ft.
Therefore, the total weight of the heavy rope is 
60×0.7 =42lb.
The work done in pulling the heavy rope to the top of the building is w = Fd.
Where 
F is force is measured in pounds;42lb
d is distance through which the heavy rope is to be pulled measured in feet; 140ft
w= 42lb×140ft= 5880lb-ft