A horizontal board of length 6.1 m and mass 12.8 kg rests on two supports. The first support is at one end of the board. The second support is at a distance of 2.38 m from the other end of the board. What force does this second support exert on the board

102.84 N

Explanation:

Given

Mass of board

Length of board

First support is at one end and second support is at a distance of 2.38 m from the other end

Suppose and are the reactions at the two support

Taking moment about the first end we can write

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