Answer:
We know there's two forces acting on a book while it sits on a table:the force of gravity pulling it down, and the normal force of the table acting upward on the book. The book isn't accelerating while it sits there. That's because the weight of the book is being counteracted by the normal force of the table.
Explanation:
There are two forces acting upon the book. One force - the Earth's gravitational pull - exerts a downward force. The other force - the push of the table on the book (sometimes referred to as a normal force) - pushes upward on the book.
Because way back, when there were some kinds of plants that made
their own food, and other kinds of plants that depended on dinosaurs or
people to bring them food, guess which ones starved and became extinct,
and which ones lived and are still among us today.
Contact forces is the answer
a the atom loses 1 proton to have a total of 34
Answer:
a

b

c
Explanation:
From the question we are told that
The angle of incidence is 
The refractive index of water is 
Generally Snell's law is mathematically represented as

Here
is the refractive index of air with value 
is the angle of refraction
So
![\theta _2 = sin^{-1}[\frac{n_1 * sin(\theta _1)}{n_2} ]](https://tex.z-dn.net/?f=%5Ctheta%20_2%20%20%3D%20%20sin%5E%7B-1%7D%5B%5Cfrac%7Bn_1%20%2A%20sin%28%5Ctheta%20_1%29%7D%7Bn_2%7D%20%5D)
=> ![\theta _2 = sin^{-1}[\frac{1.3 * sin(10)}{1} ]](https://tex.z-dn.net/?f=%5Ctheta%20_2%20%20%3D%20%20sin%5E%7B-1%7D%5B%5Cfrac%7B1.3%20%2A%20sin%2810%29%7D%7B1%7D%20%5D)
=> 
Given that the angle should not be greater than
then the angle of incidence will be
![\theta _1 = sin^{-1}[\frac{n_2 * sin(\theta _2)}{n_1} ]](https://tex.z-dn.net/?f=%5Ctheta%20_1%20%20%3D%20%20sin%5E%7B-1%7D%5B%5Cfrac%7Bn_2%20%2A%20sin%28%5Ctheta%20_2%29%7D%7Bn_1%7D%20%5D)
=> ![\theta _1 = sin^{-1}[\frac{1 * sin(45)}{1.3} ]](https://tex.z-dn.net/?f=%5Ctheta%20_1%20%20%3D%20%20sin%5E%7B-1%7D%5B%5Cfrac%7B1%20%2A%20sin%2845%29%7D%7B1.3%7D%20%5D)
=> 
Generally for critical angle is mathematically represented as
![\theta_c = sin^{-1}[\frac{n_2}{n_1} ]](https://tex.z-dn.net/?f=%5Ctheta_c%20%20%3D%20%20sin%5E%7B-1%7D%5B%5Cfrac%7Bn_2%7D%7Bn_1%7D%20%5D)
=>
=>