If the charge q is placed at the centre of the line joining two equal charges Q such that the system is in equilibrium then the value of q is?  Really need it, with a good explanation, will appreciate such answer. ​

q is 0

Explanation:

Now another charge q is placed at the middle point of the line and the system is in equilibrium, that means net force on charge q is 0

Let's just suppose this situation, so it's like this;

Q q Q

Now, acc. to the question, the system is equilibrium which means that possibly both the Q should be exerting some pressure on the middle charge q, so let's suppose Q be +ve and q be -ve

The charge that we have kept at a certain distance something like this;

+Q -q +Q

<––– d ––– > <––– d ––– >

Now, we +Q will be exerting some force on the another +Q that it should be acc. to columbs law like this;

F = k × Q1Q2/r²

F = k × QQ/(2d)²

F1 = k × Q²/4d²

Also, when this +Q will exert force on -q, it could be written as;

F = k × Q1Q2/r²

F2 = k × Qq/d²

From the question, we know that the system is a equilibrium which means that these two force F1 and F2 will be equal to each other;

= k × Q²/4d² = k × Qq/d²

= Q/4 = q

= Q/4 = -q

= -Q/4 = q

So, the charge on q is -Q/4. :)

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.

answerdmitry mendeleyev made a workable classification of the elements