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 !
Answer:

Explanation:
A force exerts work when there is a displacement of its point of application in the direction of that force. Therefore, the work done by a system is defined as the inner product between the applied force and the displacement:

In this case, we have:

So, replacing this:

Answer:
speed will double
Explanation:
Tangential velocity is given by
v=wr
where r is radius and w is rotational velocity. When r is increased to 2R, keeping roational velocity constant, the tangential velocity doubles. Hence unwinding will take place at a twice the rate and the final velocity will be double
Answer:
Fruit Punch
Explanation:
A pure substance is whereby there is only one type of element or a compound in the periodic table in the substance.
Carbon: Well its just C in the periodic table, so this is definitely pure.
Water Molecule: What makes water? H2O right? Contains Hydrogen and Oxygen, and as we all know H2O is a compound, therefore this is a pure substance.
Fruit Punch: What makes fruit punch, water and fruits. Fruits may contain citric acid(a compound itself), and is mixed with water with already has a compound, so having 2 different compounds will result in a mixture and therefore it will not be pure.