Answer:
Pressure on both feet will be
Explanation:
Weight of the person F = 500 N
Area of foot print 
Area of both the foot 
We have to find pressure on both the feet
Pressure is equal to ratio of force and area
So pressure 

So the pressure on both feet will be
when person stands on both feet.
Air pressure pushing in on the balloon decreases as the balloon rises.
Answer:
According to Coulomb's Law, the potential energy of two charged particles is directly proportional to the product of the two charges and inversely proportional to the distance between the charges
Explanation:
According to Coulomb's Law, the potential energy of two charged particles is directly proportional to the product of the two charges and inversely proportional to the distance between the charges. Since the potential energy of two charged particles is directly proportional to the product of the two charges, its magnitude increases as the charges of the particles increases. For like charges, the potential energy is positive(the product of the two alike charges must be positive) and since potential energy is inversely proportional to the distance between the charges therefore it decreases as the particles get farther apart . For opposite charges, the potential energy is negative(the product of the two opposite charges must be negative) and since potential energy is inversely proportional to the distance between the two charges, it becomes more negative as the particles get closer together.
The period of the pendulum is the reciprocal of the frequency:

The period of the pendulum is given by

where L is the length of the pendulum, and g the acceleration of gravity. By re-arranging the formula and using the value of T we found before, we can calculate the length of the pendulum L:
Examples of Newton's three law of motion.
First law of motion: A rocket being launched up in the atmosphere.
Second law of motion:while riding a bicycle, a bicycle acts as a mass and our legs pushing on the pedals of the bicycle is the force.
Third law of motion:when we jump off from the boat,the boat moves backward.
Hope,it will helpyouu!