Answer: Option (b) is the correct answer.
Explanation:
It is known that when a ray of light tends to travel from a denser to rarer medium then there occurs total internal reflection.
For a denser medium the refractive index is greater than that of a rarer medium. This means that for the given situation refractive index of medium 
is greater than medium 
.
this also means that incident angle must be greater than the critical angle of the medium.
Thus, we can conclude that the statement > must be true for total internal reflection to occur.
Answer:
Assume two identical cans filled with two types of soup having same mass are rolling down on an inclined plane in same conditions. In terms of inertia different types of soup will indicate different viscosity. The higher viscosity fillings indicates more part of the soup mass is rotating together with the can’s body. This means that for the can with lower viscosity soup has a lower moment of inertia and the can with higher viscosity has higher moment of inertia while the same gravity makes them to roll.
incline angle = θ ; can's mass = m ; Radius of the can's = R , Angular acceleration for Can 1 = α1 ; Angular acceleration for Can 2 = α2
T1 = Inertia of Can with high viscosity soup
T2 = Inertia of Can with low viscosity soup
M1 rolling moment of Can 1
M2 rolling moment of Can 2
equation is given by
T1*α1 = M1 - (a)
T2*α2 = M2 - (b)
M1 = M2 = m*g*R*sin(θ). (c)
as assumed T1 > T2
from the three equation (a), (b) & (c)
the α2 > α1
Angular acceleration of Can 2 is higher than Can 1. Already stated that Can 1 has more viscous soup as compared to Can 2.
Lead-207 can change into Lead-208.
When Lead-207 is bombarded with neutrons, the atom acquires the neutron. Adding a neutron only changes the mass number of the atom. This does not involve change in the identity of the atom. So, Lead-207 can change into Lead-208 without change in its chemical properties.
B, do earthworms prefer bright light or darkness!
