**Balancing the See-Saw: A Physics Problem**

To balance the see-saw, we need to ensure that the torque on both sides of the pivot point is equal. Torque is calculated by multiplying the force applied by the distance from the pivot point.

**1. Calculating the Torque of the Boy:**
The boy weighs 4 N and sits at a distance of 1 m from the center of the see-saw. The torque of the boy can be calculated as follows:

Torque of the boy = Force * Distance
= 4 N * 1 m
= 4 N.m

**2. Balancing the Torque:**
To balance the see-saw, the torque exerted by the girl on the other side of the see-saw should be equal to the torque exerted by the boy.

**3. Calculating the Torque of the Girl:**
Let's assume the distance at which the girl should sit from the center of the see-saw is represented by x meters. The torque of the girl can be calculated as follows:

Torque of the girl = Force * Distance
= 2 N * x m
= 2x N.m

**4. Equating the Torques:**
To balance the see-saw, the torque of the girl should be equal to the torque of the boy. Therefore, we can equate the two torques:

2x N.m = 4 N.m

**5. Solving for x:**
To find the position x at which the girl should sit, we can solve the equation:

2x = 4

Dividing both sides by 2, we get:

x = 2

Therefore, the girl should sit at a distance of 2 meters from the center of the see-saw on the other side, in order to balance the weight of the boy.

**Conclusion:**
To balance the see-saw with a boy weighing 4 N sitting at a distance of 1 m from the center, a girl weighing 2 N should sit at a distance of 2 m from the center on the other side. This will ensure that the torques on both sides of the pivot point are equal, resulting in a balanced see-saw.

ANS: 2m

Because when she sits near the centre the weight will be doubled.

(DISTANCE DECRASES FORCE IS DOUBLED).