What is meant by absolute time? why was it not noticed before the development of the special theory of relativity?

Absolute time is placing a number on an object or event. It would be like saying this fossil is 500,000,000 millions years old or a volcanic eruption took place 200,000 years ago. Absolute time is expressed in numbers.

Newton's assumptions were perfectly rational, considering the prevailing knowledge at the time he lived. His conclusions were absolutely revolutionary, and his work is still used on a daily basis by engineers designing everything from skateboards to spacecraft. 

The answer is 4f======since electrostatic force is given by    we let f be the electrostatic force when  r = 1 m    if we let  denote the electrostatic force when the distance is decreased so that r = 0.5m, then    we established earlier that f = kq₁q₂. therefore    the force will now be 4f.