The "objective" (lens or mirror) is the major major major part of
the optical telescope. It's really the only part you need in order
to make a telescope (besides something to hold the objective).
You can put a piece of film or a CCD right at the focal point of
the objective lens or mirror and capture 'images' (pictures) there.
If you want to use the telescope for looking through and seeing stuff
with your eye, then you need the other major part ... the eyepiece lens.
C is what i would go with
Answer:
a.3Hz
b.0.0034m
Explanation:
First, we know the flute is an open pipe, because open pipe as both end open and a close organ pipe as only one end close.
The formula relating the length and he frequency is giving as
.
a.we first determine the length of the flute at the fundamental frequency i.e when <em>n</em>=1 and when the speed is in the 342m/s
Hence from
.
since the value of the length will remain constant, we now use the value to determine the frequency when the air becomes hotter and the speed becomes 345m/s.

Hence the require beat is
.
b. since the length is dependent also on the speed and frequency, we determine the new length when she plays with a fundamental frequency when the speed of sound is 345m/s
using the formula
Now to determine the extension,

Well I think B hope this helps