Answer:
1.696 nm
Explanation:
For a diffraction grating, dsinθ = mλ where d = number of lines per metre of grating = 5510 lines per cm = 551000 lines per metre and λ = wavelength of light = 467 nm = 467 × 10⁻⁹ m. For a principal maximum, m = 1. So,
dsinθ = mλ = (1)λ = λ
dsinθ = λ
sinθ = λ/d.
Also tanθ = w/D where w = distance of center of screen to principal maximum and D = distance of grating to screen = 1.03 m
From trig ratios 1 + cot²θ = cosec²θ
1 + (1/tan²θ) = 1/(sin²θ)
substituting the values of sinθ and tanθ we have
1 + (D/w)² = (d/λ)²
(D/w)² = (d/λ)² - 1
(w/D)² = 1/[(d/λ)² - 1]
(w/D) = 1/√[(d/λ)² - 1]
w = D/√[(d/λ)² - 1] = 1.03 m/√[(551000/467 × 10⁻⁹ )² - 1] = 1.03 m/√[(1179.87 × 10⁹ )² - 1] = 1.03 m/1179.87 × 10⁹ = 0.000848 × 10⁻⁹ = 0.848 × 10⁻¹² m = 0.848 nm.
w is also the distance from the center to the other principal maximum on the other side.
So for both principal maxima to be on the screen, its minimum width must be 2w = 2 × 0.848 nm = 1.696 nm
So, the minimum width of the screen must be 1.696 nm
Answer:
Reflective
Explanation:
The radiation pressure of the wave that totally absorbed is given by;
and While the radiation pressure of the wave totally reflected is given by;
Now compare the two-equation you can clearly see that the pressure due to reflection is larger than absorption therefore the sail should be reflective.
Coefficients is your answer. I hope I helped:)
Answer:
Gravitational Force.
Explanation:
Being one of the fundamental forces of nature, gravitational force is the weakest but has an infinite range. It is always attractive and acts between any two pieces of matter in nature.
Answer:
v₀ = 15 m/s
Explanation:
given,
initial velocity = v₀
down acceleration of rock = 10 m/s²
rock distance
S₄ = 7 x S₁
From kinematic equations
S = v₀ t+0.5 at²
at t = 1 s
S₁ = v₀ (1)+0.5 x 10 x 1²
S₁ = v₀+ 5......(1)
at t = 4 s
S₄ = v₀ (4)+0.5 x 10 x 4²
S₄ = 4 v₀+80.....(2)
from equation (1) and (2)
7( v₀ + 5 ) = 4 v₀ +80
3 v₀ = 80 - 35
3 v₀ = 45
v₀ = 15 m/s