Answer:
Explanation:
Given
mass of water molecule 
mass of person 
It is given that body is mostly made up of water
suppose n water molecules constitutes 62 kg
so 
Answer:
The correct option is B
Explanation:
Although, it is common knowledge that in an electric field, unlike charges attract and like charges repel. However, to build up an electric potential, a positive charge is brought close to another positive charge - this causes work done to be changed to electric potential energy and stored in the electric field.
It should however be noted that when a negative charge is moved away from a positive charge, the negative charge gains electric potential energy.
The only correct statement on that list is <em>choice-C</em>: If a positively charged rod is brought close to a positively charged object, the two objects will repel.
Answer: a.) Roughness of the surfaces in contact with each other .
Higher the roughness of surfaces in contact with each other, greater is the friction between bodies. Force of friction will be less between smooth surfaces.
b.) Weight of the sliding/rolling body: greater the weight of the moving body on the surface, more is the force of friction on the body by the surface.
I hope this helps
