How to Answer This... Two conducting spheres having charges 3Q and 5Q attract each other with force of 10N. They are then seperated to the same distanece. Calculate magnitude and nature of forces?

Answer 1

-- If you know the force between them, then you don;t need to know their

charges. The 3Q and 5Q are there only to confuse you with too much info.

-- The forces act along the line between the centers of the spheres. There's

one force in each direction, acting on each sphere. The forces are equal.

The forces pull the spheres together if their charges have opposite signs,

and push the spheres apart if the charges both have the same sign. The

signs of the charges is not mentioned in the question.

-- The magnitude of the forces changes as 1/(square of the distance between the centers).

For example, if the spheres are moved 3 times as far apart, then the forces

become 1/9 as great as they were originally.

-- The question can't be answered, because the single most important piece

of information is stated in a way that's quite useless ... What does "separated

to the same distance" mean ? ? ? We need to know how the new distance

compares to the original distance, and this phrase doesn't tell us that.