Answer: 3.21 N


For weight, we will multiply by 

Hence, the rock would weigh 3.21 N.
<h2>
Answer:2.65 seconds</h2>
Explanation:
Let
be the acceleration.
Let
be the initial velocity.
Let
be the final velocity.
Let
be the time taken.
As we know from the equations of motion,

Given,


Answer:

Explanation:
= Avogadro's number = 
e = Charge of electron = 
k = Coulomb constant = 
Z = Atomic number of water = 18
M = Molar mass of water = 0.018 kg/mol
m = Mass of person
The charge is given by

Total number of protons and electrons in each sphere




Electrical force is given by

The electrostatic force of attraction between them is 
The answer is ultra violet radiation. From the air