36. Two point charges are separated by 6 cm. The attractive force between them is 20 N. Find the force between them when they are separated by 12 cm. (Why can you solve this problem without knowing the magnitudes of the charges

The force between two charges when they are separated by distance 12 cm is    

Explanation:

Here lets us consider two charges and .

Let  be the force between them when they are separated by distance 6 cm

      be the force between them when distance between them = 12 cm

             =20 N     ..................1

                            ...................2

 Dividing both equations , we get

    .

Here we need not to know the values of charges , since they get cancelled while dividing.

answer: option c.

explanation:

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.