The distance between the 1st and 2nd maxima is 0.3 cm when the screen is located 2 m away. if d = 0.4 mm, a) what is the wavelength?
b) what is the size of central peak?

a) The wavelength of light is 6×10^-7 m.

b) The size of the central peak is 6×10^-3 m.

Explanation:

let:

α be the distance between the 1st and 2nd maxima

d = 0.4 mm be the grating slit space

X be the distance to the screen

a) α = λ×X/d

   λ = α×d/X

      = (0.3×10^-2)×(0.4×10^-3)/(2)

      = 6×10^-7 m

Therefore, the wavelength of light is 6×10^-7 m.

b) the size of the central peak is given by:

 D = 2×λ×X/d

     = 2×(6×10^-7)×(2)/(0.4×10^-3)

     = 6×10^-3 m

Therefore, the size of the central peak is 6×10^-3 m.

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards