In the gure below, two isotropic point sources of light (S1 and S2) are separated by distance 2.70 mm along a y-axis and emit in phase at wavelength 900 nm and at the same amplitude. A light detector is located at point P at coordinate xP on the x-axis. What is the greatest value of xP at which the detected light is minimum due to destructive interference

The figure is missing, so i have attached it.

The distance between S1 and S2 is 2.70μm

7.88 μm

Explanation:

Let the distance in question be x.

The path difference between rays starting from S1 and S2 up to points on the x axis when x is greater than zero is given as;

(√(d² + x²)) - x = (m + ½)λ

Making x the subject of the formula, we have;

x = (d²/(2m + 1)λ) - (2m + 1)λ/4

m is an integer e.g, 0,1,2..

The greatest value of xP will be at m = 0

Thus, putting m = 0,we have;

x = (d²/λ) - (λ/4)

We are given;

d = 2.70 μm = 2700 nm

λ = 900 nm

Thus;

x = (2700²/900) - (900/4)

x = 7875 nm = 7.875 μm ≈ 7.88 μm

gpe = mass x gravity constant x height or… gpe = mgh

where… mass: measured in kilograms (kg)

gravity: gravity constant on earth = 10.00 m/s2

height: measured in meters (m)

gpe: measured in joules (j) or kilojoules (kj)

how do you solve gpe?

gravitational potential energy (gpe) is the energy an object has because of its position above the. ground.

gpe = mass x gravity constant x height or… gpe = mgh.

mass:

note: to earn full marks when solving science word problems, you must show your work:

formula.

example:

given values:

mass = 0.3 kg.

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it