I think it occurs whenever waves come together so that they are in phase with each other.
The first: alright, first: you draw the person in the elevator, then draw a red arrow, pointing downwards, beginning from his center of mass. This arrow is representing the gravitational force, Fg.
You can always calculate this right away, if you know his mass, by multiplying his weight in kg by the gravitational constant

let's do it for this case:

the unit of your fg will be in Newton [N]
so, first step solved, Fg is 637.65N
Fg is a field force by the way, and at the same time, the elevator is pushing up on him with 637.65N, so you draw another arrow pointing upwards, ending at the tip of the downwards arrow.
now let's calculate the force of the elevator

so you draw another arrow which is pointing downwards on him, because the elevator is accelating him upwards, making him heavier
the elevator force in this case is a contact force, because it only comes to existence while the two are touching, while Fg is the same everywhere
Explanation:
It is given that,
Diameter of the peach pie, d = 9 inches
Radius of the pie, r = 4.5 inches
The tray is rotated such that the rim of the pie plate moves through a distance of 183 inches, d = 183 inches
Let
is the angular distance that the pie plate has moved through.
It is given by :


Since, 1 radian = 57.29 degrees

Since, 1 radian = 0.159155 revolution

Hence, this is the required solution.
What is an example of how you can use scientific inquiry to solve a real life problem.
Geothermal energy provides force that causes magma to erupt to the surface