In physics, work is defined as the total energy when an object is moved to a certain displacement by the application of external force. It is calculated by the expression W = Fd. For this case, the displacement is apparently zero, then there is no work in the system above.
Answer:
exerts force
Explanation:
The accumulation of excess electric charge on an object is called static electricity. ... An electric field surrounds every electric charge and exerts the force that causes other electric charges to attract or repel. Electric fields are represented by arrows showing the electric field would make a positive charge move.
Answer:
ion
Explanation:
when ever an atom or group of atoms get charge they are called ion or ions
It really depends on what the bulb is being used for, since efficiency means how much of the output is USEFUL.
If the bulb is being used for light in a dark room, then it produces (8.2% x 21W) = 1.72 joules per second of light energy.
If the bulb is being used to keep a hamster cage or a fish tank warm, then the 8.2% is the useful part, and the light is the other (91.8% x 21W) = 19.28 joules per second.
