HELP ASAP Mark and Steven were conducting an investigation where they were measuring the energy of a glass marble as it rolled down a ramp. According to their calculations, the total energy of the marble decreased. Which statement below is the best explanation for the decrease in total energy?
A) It decreased because it was destroyed by the interaction with the ramp
B) The total energy always decreases in an energy conversion
C) They were incorrect; the energy totals should have been the same
D) The energy decreased because heat resulted from friction between the marble and the ramp

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