Brody and ethel are arguing about waves. brody says that waving his hand back and forth is a scientific wave. ethel says that it is not. which statement best describes who is correct?
-brody is correct because the wave involves an input of energy.
-ethel is correct because energy is not carried from one place to another.
-brody is correct because the pattern repeats.
-ethel is correct because the motion has no pattern.



khalad is measuring the amplitude of a wave. what can be known about this wave?
-it is a sound wave.
-it is a transverse wave.
-it is an electromagnetic wave.
-it is a mechanical wave.

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

pecialized keyboards