A) experimental because he isn’t sure and is testing out
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:
The rate of change of the area when the bottom of the ladder (denoted by
) is at 36 ft. from the wall is the following:

Explanation:
The Area of the triangle is given by
where
(by using the Pythagoras' Theorem) and
is the length of the base of the triangle or the distance between the bottom of the ladder and the wall.
The area is then

The rate of change of the area is given by its time derivative


Product rule
Chain rule


In here we can identify
,
and
.
The result is then

Answer:
Sound waves are pushed closer together, decreasing wavelength
and increasing frequency.
I’m pretty sure it’s average speed= total distance and total time which is A.