Answer:
Let the second medium be air (n₁=1)
The refractive index n₂ of the medium where first medium is air is found (a)
(a) n₂ = 2
Explanation:
Critical angle can be defined as the angle of incidence that provides the angle of refraction of 90°.
Refractive index of a medium can be defined as a number that describes that how fast a light will travel through that medium.
Critical angle and Refractive index are related by:


To find refractive index of medium with respect to air, substitute n₁=1 (Refractive index of air is 1)
Also θ(critical)=30°
Find n₂ :

Answer: C
Explanation: Amplitude controls loudness, and frequency controls pitch. The more frequent the higher pitch.
Answer:
0.266 m
Explanation:
Assuming the lump of patty is 3 Kg then applying the principal of conservation of linear momentum,
P= mv where p is momentum, m is mass and v is the speed of an object. In this case
where sunscripts p and b represent putty and block respectively, c is common velocity.
Substituting the given values then
3*8=v(15+3)
V=24/18=1.33 m/s
The resultant kinetic energy is transferred to spring hence we apply the law of conservation of energy
where k is spring constant and x is the compression of spring. Substituting the given values then

now you justhave to solve the last numbers because...Iam sooo Lazy right now
In physical chemistry, the terms body-centered cubic (BCC) and face-centered cubic (FCC) refer to the cubic crystal system of a solid. Each solid is made up simple building blocks called lattice units. There are different layouts of a lattice unit.
It is better understood using 3-D models shown in the picture. A BCC unit cell has one lattice point in the center, together with eight corner atoms which represents 1/8 of an atom. Therefore, there are 1+ 8(1/8) = 2 atoms in a BCC unit cell. On the other hand, a FCC unit cell is composed of half of an atom in each of its faces and 1/8 of an atom in its corners. Therefore, there are (1/2)6 + (1/8)8 = 4 atoms in a FCC unit cell.