When 150 joules of work is done on a system by
an external force of 15 newtons in 20. seconds,
the total energy of that system increases by
(1) 1.5 x 10
(3) 3.0 x 10)
(2) 2.0 x 10-
(4) 2.3 x 103]

If its history of, then b) because a) implies only present day (now)

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.

The force is push or pull

Decrease the surface area of the object and also decrease the concentration which will allow the particles to collide faster