Answer:
10.2 m
Explanation:
The position of the dark fringes (destructive interference) formed on a distant screen in the interference pattern produced by diffraction from a single slit are given by the formula:

where
y is the position of the m-th minimum
m is the order of the minimum
D is the distance of the screen from the slit
d is the width of the slit
 is the wavelength of the light used
 is the wavelength of the light used
In this problem we have:
 is the wavelength of the light
 is the wavelength of the light
 is the width of the slit
 is the width of the slit
m = 13 is the order of the minimum
 is the distance of the 13th dark fringe from the central maximum
 is the distance of the 13th dark fringe from the central maximum
Solving for D, we find the distance of the screen from the slit:

 
        
             
        
        
        
Answer:
Explanation:
Given that 
F=2x³
Work is given as 
The range of x is from x=0 to x=D
W=-∫f(x)dx
Then,
W=-∫2x³dx from x=0 to x=D
W=- 2x⁴/4 from x=0 to x=D
W=-2(D⁴/4-0/4)
W=-D⁴/2
W=1/2D⁴
The correct answer is F