Super bee , continuing to save the world from front end collisions , travels between two trains that are initially 4 kilometers apart. If one is traveling at a speed of 100 kilometers/hour and the second train is traveling in the opposite direction at 120 kilometers/hour, how long will super bee be flying ?

magnitude and direction

the answer is f1 and d2 because if you put equal force on those two points the beam would balance trust me on this

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