Answer:
Night vision is the ability to see in low-light conditions. Whether by biological or technological means, night vision is made possible by a combination of two approaches: sufficient spectral range, and sufficient intensity range.
V: velocity of wave
f: frequency
L: wavelenght
v = fL => L = v/f => L = (3x10^8)/(900x10^3) => L = 3.33 x 10^2m
Answer:

Explanation:
I = Moment of inertia = 
m = Mass of two atoms = 2m = 
r = distance between axis and rotation mass
Moment of inertia of the system is given by

The distance between the atoms will be two times the distance between axis and rotation mass.

Therefore, the distance between the two atoms is 
Answer:
Explanation:
From the given information:
The initial PE
= m×g×h
= 5 kg × 9.81 m/s² × 10 m
= 490.5 J
The change in Potential energy P.E of the box is:
ΔP.E = 
ΔP.E = 0 -
ΔP.E = 
If we take a look at conservation of total energy for determining the change in the internal energy of the box;


this can be re-written as:

Here, K.E = 0
Also, 70% goes into raising the internal energy for the box;
Thus,


ΔU = 343.35 J
Thus, the magnitude of the increase is = 343.35 J
Explanation:
Given that,
The optical power of the equivalent single lens is 45.4 diopters.
(a) The relationship between the focal length and the focal length is given by:


f = 0.022 m
or
f = 2.2 cm
(b) We need to find how far in front of the retina is this "equivalent lens" located. It is given by using lens formula as :

Here, u = infinity

v = 2.2 cm
So, at 2.2 cm in front of the retina is this "equivalent lens" located.
Hence, this is the required solution.