Answer:
constructive interference in which waves strengthen each other
Explanation:
Some definitions:
- Costructive interference occurs when two (or more) waves meet each other in phase, so with same displacement at the same point. In such situation, the two waves strengthen each other, and the amplitude of the resultant wave is the sum of the amplitudes of the individual waves
- Destructive interference occurs when two waves meet each other in anti-phase, so with opposite displacement at the same point. In such situation, the two waves cancel each other out, and the amplitude of the resultant wave is the difference of the amplitudes of the individual waves (which means zero if the two waves are identical)
For light waves interfering with each other, 'white' means costructive interference, while 'black' means destructive interference (because black is absence of colors, so this means that the waves cancel each other out). In this problem, we see that point X, Y and X are white, therefore they are point of constructive interference, where the waves strengthen each other.
Answer
Any force greater 490N
Explanation
The force required just to make an object slide over a rough horizontal surface is any force greater that the static friction which given by;

Given;

Hence;
F = 0.5 x 100 x 9.8
F = 490N.
We will only need the coefficient of kinetic friction if we were asked to find the force required to keep the object moving uniformly. Usually, the force needed to keep an object moving uniformly over a rough surface is lesser that which is needed to start its motion.
In this problem, we were only asked to find the minimum force required to make the object move which we have done.
Answer:

Explanation:
Given:
volume of air in the room, 
temperature of the room, 
<u>Saturation water vapor pressure at any temperature T K is given as:</u>
<u />
<u />
putting T=298 K we have

<u>The no. of moles of water molecules that this volume of air can hold is:</u>
Using Ideal gas law,



is the maximum capacity of the given volume of air to hold the moisture.
Currently we have 80% of n, so the mass of 20% of n:

where;
M= molecular mass of water

is the mass of water that can vaporize further.
In chemical reactions, electrons are transferred.
While in nuclear reactions, protons and neutrons are the ones transferred.
Hope this helps.<span />
There are three main factors that affect wave formation: wind velocity, fetch, and duration.
Waves are most commonly caused by wind. Wind-driven waves, or surface waves, are created by the friction between wind and surface water. As wind blows across the surface of the ocean or a lake, the continual disturbance creates a wave crest.