Working of a Half wave rectifier
The diode is connected in series with the secondary of the transformer and the load resistance RL. The primary of the transformer is being connected to the ac supply mains. The ac voltage across the secondary winding changes polarities after every half cycle of the input wave.
To solve the problem it is necessary to apply the Malus Law. Malus's law indicates that the intensity of a linearly polarized beam of light, which passes through a perfect analyzer with a vertical optical axis is equivalent to:

Where,
indicates the intensity of the light before passing through the polarizer,
I is the resulting intensity, and
indicates the angle between the axis of the analyzer and the polarization axis of the incident light.
Since we have two objects the law would be,

Replacing the values,



Therefore the intesity of the light after it has passes through both polarizers is 
Answer:

Explanation:
Two identical bodies are sliding toward each other on a frictionless surface.
Initial speed of body 1, m₁ = 1 m/s
Initial speed of body 2, m₂ = 2 m/s
They collide and stick.
We need to find the speed of the combined mass. Let V is the speed of the combined mass.
Using the conservation of momentum.

We have, m₁ = m₂ = m

So, the speed of the combined mass is
.
The complete statement is
As a solid element melts, the atoms become more separated and they have less attraction for one another.
Let me explain to you how this happens. In solid phase. Its molecules are arranged in a very compact manner that is why it takes a definite shape and volume. When it is heated, the kinetic energy of the molecules increases. This is characterized by more frequent collisions. The rise in temperature causes the molecules to move rapidly by vibrating. When it reaches an amount of energy that causes the solid to change phase, this is called the latent energy. The molecules break their form and move farther away from each other until it resembles that of a liquid melting. At this point, the molecules would have lesser attraction because of the distance between them.