1. Frequency: 
The frequency of a light wave is given by:

where
is the speed of light
is the wavelength of the wave
In this problem, we have light with wavelength

Substituting into the equation, we find the frequency:

2. Period: 
The period of a wave is equal to the reciprocal of the frequency:

The frequency of this light wave is
(found in the previous exercise), so the period is:

Answer: 0K
Explanation:
Absolute 0 (0K) is the point where nothing could be colder and no heat energy remains in a substance.
Answer:

Explanation:
Given that,
Lightning flashes one mile (1609 m) away from you.
We need to find the time it take the light to travel that distance. Let the time be t. We know that,
speed = distance/time

So, the required time is 
The equilibrium condition allows finding the result for the force that the chair exerts on the student is:
- The reaction force that the chair exerts on the student's support is equal to the student's weight.
Newton's second law gives the relationship between force, mass and acceleration of bodies, in the special case that the acceleration is is zero equilibrium condition.
∑ F = 0
Where F is the external force.
The free body diagram is a diagram of the forces on bodies without the details of the shape of the body, in the attached we can see a diagram of the forces.
Let's analyze the force on the chair.
Let's analyze the forces on the student.
In conclusion using the equilibrium condition we can find the result for the force that the chair exerts on the student is:
- The reaction force that the chair exerts on the student's support is equal to the student's weight.
Learn more here: brainly.com/question/18117041