Myopia
Explanation:
myopia is a common vision condition in which you can see objects near to you clearly, but objects farther away are blurry. It occurs when the shape of your eye causes light rays to refract incorrectly, focusing images in front of your retina instead of on your retina. It can be corrected corrected with eyeglasses, contact lenses or refractive surgery.
Answer : The energy of one photon of hydrogen atom is, 
Explanation :
First we have to calculate the wavelength of hydrogen atom.
Using Rydberg's Equation:

Where,
= Wavelength of radiation
= Rydberg's Constant = 10973731.6 m⁻¹
= Higher energy level = 3
= Lower energy level = 2
Putting the values, in above equation, we get:


Now we have to calculate the energy.

where,
h = Planck's constant = 
c = speed of light = 
= wavelength = 
Putting the values, in this formula, we get:


Therefore, the energy of one photon of hydrogen atom is, 
Newton's 2nd law of motion:
Force = (mass) x (acceleration)
Divide each side by (mass):
Acceleration = (force) / (mass)
= (100 N) / (50 kg)
= 2 m/s²
Answer;
Amount of time the two substances are in contact
Area in contact between the two substances
Specific heat of the material that makes up the substances
Explanation;
The change in temperature of a substance is caused by heat energy. The change in temperature will depend on factors such as mass of the substance, the type of material it is made from, the time taken , specific heat of the material that makes the substance, and also the area of contact.
The amount of time the two substances are in contact affect the change in temperature such that if the two bodies are in contact for a longer time then a bigger change in temperature will be observed.
Specific heat capacity also determines the change in temperature that will be observed, such that a substance with a bigger specific heat capacity will record a small change in temperature.
Answer:
When the Earth and sun are perfectly lined up, then it will happen. They can tell when it's going to happen.
Explanation:
This is why it only happens in some places. Some days it's not sunny out, so it's not going to happen.