if a crater were 100 feet wide, about how deep would it be?

Question

most craters on the moon ate about 1/5(.20) as latge as they ate wide.

Answer 1

Too many variables. Mainly the nature and consistency of the ground and the nature, speed and weight of the object which produced the crater (a meteorite?).
Then you have volcanic craters. Again, too many variables!

Answer 2

This is a very hard question to answer based upon
the information you provided. What we need to know
is where this crater is located and, roughly, what the
composition of the surface that was hit is.

In a really simple estimate which disregards all the
above, let us suppose that the object hit with enough
velocity to submerge itself completely in the surface
material. Further let us assume that the crater became
one half of a perfect sphere. In that case, the width of
the crater (100 feet) is the hemisphere's diameter,
and the radius would be half of that, or 50 feet. The
crater would be 50 feet deep. That does not mean that
the asteroid or meteor only penetrated 50 feet. It means
that the disturbance of the surface material formed a dish whose diameter was 100 feet wide and 50 feet deep. The
meteor itself could have penetrated several hundreds of feet into the surface.

Regards,
Zah

Answer 3

It depends on the size of the asteroid that hit, and the velocity at which it hit. Just saying that a crater is 100 feet wide doesn't really help.

Answer 4

you haven't specified where it is; on the moon the figure will be different to that one earth due to differences in gravity