Molarity and molality both describe the concentration of a substance in terms of moles.
Molarity describes the number of moles of a substance per unit of volume, typically per liter (mol/l).
Molality describes the number of moles per unit of mass, typically kilograms (mol/kg).
When determining the molality of a solution, mol/kg can be obtained by finding the number of moles in the substance, and dividing that number by the the total weight in kilograms of that substance.
When determining the molarity of a solution, mol/l can be obtained by dividing the number of moles in a substance by the total volume in liters of that substance.
The electromagnetic spectrum is traditionally divided into regions of radio waves, microwaves, infrared radiation, visible light, ultraviolet rays, x rays, and gamma rays. ... Wavelength defines the distance between adjacent points of the electromagnetic wave that are in equal phase (e.g., wavecrests)
Answer: 
Explanation:
Given
Mass of the elevator is 
Time period of ascension 
cruising speed 
Distance moved by elevator during this time
Suppose Elevator starts from rest

Distance moved

Gain in Potential Energy is

Average power during this period is

Answer:
a) d₁ = 247.8 μm
d₂ = 205.3 μm
b) d₂ = 20.53 x 10⁻⁵ m = 205.3 μm
Explanation:
a)
The formula for Michelson Interferometer is derived to be:
d = mλ/2
where,
d = distance moved
m = no. of fringes
λ = wavelength of light
For JAN, we have following data
d = d₁
m = 818
λ = 606 nm = 606 x 10⁻⁹ m
Therefore,
d₁ = (818)(606 x 10⁻⁹ m)/2
<u>d₁ = 24.78 x 10⁻⁵ m = 247.8 μm</u>
For LINDA, we have following data
d = d₂
m = 818
λ = 502 nm = 502 x 10⁻⁹ m
Therefore,
d₂ = (818)(502 x 10⁻⁹ m)/2
<u>d₂ = 20.53 x 10⁻⁵ m = 205.3 μm</u>
b)
The resultant displacement can be found out from the difference between both displacement. And the direction of resultant displacement will be the same as the direction of greater displacement. Therefore,
Resultant Displacement = Δd = d₁ - d₂
Δd = 247.8 μm - 205.3 μm
<u>Δd = 42.5 μm (in the direction of JAN)</u>