The index of refraction of a certain liquid is 2.1. What is the critical angle for a light ray traveling in this liquid toward a flat layer of air above it?

28.42°

Explanation:

Critical Angle:This is the incident angle at which the angle of refraction is 90° when light passes from denser to less dense medium

from Refraction,

1/n = sinc Equation 1

Where n = refractive index of the liquid, c =  critical angle.

make c the subject of the equation

c = sin⁻¹(1/n) Equation 2

Given: n = 2.1

Substitute the value of n into equation 2

c = sin⁻¹(1/2.1)

c = sin⁻¹(0.476)

c = 28.42°

Hence the critical angle = 28.42°

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.

hi there!

out of the two, (b) precision would be more reasonable.   however, both a and b could be pretty reasonable.

-awesomerepublic   : )