Answer: C and D
Explanation: One of the first rule for total internal reflection to occur is that the ray must move from a dense to a less dense medium, hence refractive index of medium a must be greater than that of b.
When a ray moves from a dense to a less dense medium, the refracted ray moves away from the normal thus increasing the size of the angle of refraction (total internal refraction occurs when the angle of refraction is 90° and the angle of incidence at this point is known as the critical angle), hence the angle of incidence must be greater than the critical angle.
These points verifies option C and D
Answer:
Explanation:
Given
speed of Electron 
final speed of Electron 
distance traveled 
using equation of motion

where v=Final velocity
u=initial velocity
a=acceleration
s=displacement


acceleration is given by 
where q=charge of electron
m=mass of electron
E=electric Field strength

A machine can never be 100% efficient because some work is always lost
due to the lack of materials or equipment that would convert work by 100%. It follows
the second law of entropy. The ideal engine is known as Carnot’s engine having
a 100% efficiency. So far, no engine has ever gotten to 100%.
Answer:
An element is a pure substance and is made of only one type of atom; it cannot be broken down into a simpler substance.
The momentum of the
x-ray photon is p = h/lambda . Lambda is the wavelength (0.30nm=3x10^(-9)m) and
h is Planck's constant,(h=6.62607004 × 10-34<span> m2 kg / s).The
momentum is: 2.2 x 10^(-25).</span>
The momentum can be calculated
also as: p=mv, where m is the mass of the electron and v is the speed.
So v=p/m,p is known,and
also the mass of the electron (m=9.10938356 × 10-31<span> kilograms).</span>
v=2.2 x 10^(-25)/9.10938356
× 10-31<span> kilograms=0.24 x 10^6 m/s</span>