What is young’s interference? (b) how should the number of observable interference fringes change as the distance between the two slits increases? assume that the slit width remains unchanged. (c) how should the number of observable interference fringes change as the slit width decreases? assume that the slit separation remains unchanged. (d) what is a missing fringe?

b) increase.

c) decrease.

d) Fringe is said to be a missing fringe  when interference maxima overlap with diffraction minima.

Explanation:

a ) Young's interference is the interference phenomenon related to the light waves. Interference  is the superposition of light waves . It proved the wave nature of light .  Interference can be either constructive or destructive.

b) If the distance between the two slits increases, the number of fringes also increases. d sinθ = m λ. Here d is the slit width and m is the order of fringes. It shows that as d increases, m also increases.

c) Similarly, as d decreases , number of fringes decrease.

d) Fringe is said to be a missing fringe  when interference maxima overlap with diffraction minima.

the focus of lesson 1 is newton's first law of motion - sometimes referred to as the law of inertia. newton's first law of motion is often stated as. an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

explanation:

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.