An object of known mass m with speed v0 travels toward a wall. the object collides with it and bounces away from the wall in the opposite direction in which the object was initially traveling. the wall exerts an average force f0 on the object during the collision. a student must use the equation δp⃗ =f⃗ δt to determine the change in momentum of the object from immediately before the collision to immediately after the collision. which side of the equation could the student use to determine the change of the object's momentum?

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