FIGURE 1 shows a horizontal human arm lifting a dumbbell. The forearm is in equilibrium under the action of the weight of the dumbbell, the tension
in the tendon connected to the biceps muscle, and the force exerted on the
forearm itself. (For clarity, the point A where the tendon is attached is drawn
farther from the elbow than its actual position) Given the weight of the forearm
is 20 N and the mass of the dumbbell is 20 kg. The angle between the tension
force and the horizontal, is 80°. The length of the horizontal arm is 0.30 m.
The horizontal distance between elbow pivot and point A is 0.050 m. Find and
the vector and draw free body diagram for this case

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

umm its a tricky question