7. two children of mass 20 kg and 30 kg sit balanced on a seesaw with the pivot point located at the center of the seesaw. if the children are separated by a distance of 3 m, at what distance from the pivot point is the small child sitting in order to maintain the balance?

Explanation:

Given

mass of children

distance between two children

suppose  small child is at a distance of x m from  pivot point

so torque of small child and heavier child must be equal

the amount of current in the coil

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia