<u>Answer:</u>
Pressure exerted = 500 Pa
<u>Explanation:</u>
The formula for pressure is as follows:

In this case,
Force applied = 100N
Area = 40cm × 50cm = 2000cm² = 2000 × 10⁻⁴ = 0.2m²
Substituting these values into the formula:
Pressure = 
⇒ Pressure = 500 Pa
An example of something that is not a proton would be an electron. It has a negative charge and has a charge of 1.6X10^-19 Coulombs.
Explanation:
I want to say option B - Both forces can act without objects touching.
Answer:
If the temperature of the air in the balloon is less than the temperature of the air surrounding the balloon then the balloon will appear slightly deflated because of the difference in temperature.
As the temperature of the air in the balloon reaches the surrounding air temperature, then the balloon will appear to be fully inflated because the temperature of the air in the balloon is the same as the surrounding air temperature.
<span>Earth (and hence the observer) moves.</span>