In the diagram above, MN is perpendicular to ON and MP. What is the difference between the moment about N of the force of 20 Newtons applied along MP and its moment about O?
In the diagram above, a ray of light passes from glass into air, if the angle of incidence in glass is a and angle of refraction in air is \( \beta \) which of following statements is true???
A.
\( \alpha = \beta \)
B.
the efractive index of glass is \( \frac{sin\theta}{sin\alpha} \)
C.
The ray suffers total internal reflection if \( \beta \) is greater than the critical angle
D.
the efractive index of glass is \( \frac{sin\alpha}{sin\beta} \)