A girl standing on a floor would have two opposite forces acting on it. These forces are the weight and the normal force. Since no other forces are acting and that the girl is at rest, then the weight must equate to the normal force. Therefore, the supporting force would be:
F = mg = 55kg (9.81 m/s^2) = 539.55 N
The part you talk into, that converts the sound of your voice
into an electrical signal, is a tiny microphone.
-- The sound waves from your voice are ripples in the air.
-- In most microphones, there's a tiny coil of wire hanging
between the ends of a tiny magnet.
-- When the ripples in the air hit the little coil of wire, they
make it vibrate (wiggle) slightly.
-- When a coil of wire wiggles in the field of a magnet,
a current flows in the wire.
There's your electrical signal !
Mars: 0.38
weight = mass x surface gravity
multiplying your weight on Earth by the number above will give you your weight on the surface of Mars
If you weigh 150 pounds (68 kg.) on Earth, you would weigh 57 lbs. (26 kg.) on Mars
answer: derived physical quantities are those quantities that are obtained from the basic physical quantities by multiplication or division and area is one of them
