| Topic: |
Science > Physics |
| User: |
"" |
| Date: |
27 Jan 2005 02:05:53 PM |
| Object: |
Basic physics question. |
I have this homework problem that I can't figure out what it is
asking... the book never even mentions anything remotely related to
this.
I'm not asking for the answer, but just am trying to find out what to
do with the problem.
Any Help?? Thanks in advance.
Consider the following accepted constants:
Radius of the moon = 1.74e6 m.
Radius of the sun = 6.96e8 m.
Average moon-earth distance = 3.84e8 m.
Average sun-earth distance = 1.496e11 m.
a) What is the apparent angle the diameter
of the moon subtends, as seen from the earth,
in radians?
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| User: "Midtown" |
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| Title: Re: Basic physics question. |
27 Jan 2005 02:28:39 PM |
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<adamray@gmail.com> wrote in message
news:1106856353.041507.171140@f14g2000cwb.googlegroups.com...
I have this homework problem that I can't figure out what it is
asking... the book never even mentions anything remotely related to
this.
I'm not asking for the answer, but just am trying to find out what to
do with the problem.
Any Help?? Thanks in advance.
Consider the following accepted constants:
Radius of the moon = 1.74e6 m.
Radius of the sun = 6.96e8 m.
Average moon-earth distance = 3.84e8 m.
Average sun-earth distance = 1.496e11 m.
a) What is the apparent angle the diameter
of the moon subtends, as seen from the earth,
in radians?
1. has nothing to do with sun, does it?
2. asking for an angle, of moons diam as seen from earth.
3 draw a diagram, simple trig functions
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| User: "CWatters" |
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| Title: Re: Basic physics question. |
28 Jan 2005 02:45:44 AM |
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<adamray@gmail.com> wrote in message
news:1106856353.041507.171140@f14g2000cwb.googlegroups.com...
I have this homework problem that I can't figure out what it is
asking... the book never even mentions anything remotely related to
this.
I'm not asking for the answer, but just am trying to find out what to
do with the problem.
I believe they gave you too much info. To answer the question you posted you
only need to know...
Radius of the moon = 1.74e6 m.
Average moon-earth distance = 3.84e8 m.
The rest might be for another part of the question?
Hints
a) Look up the definition of "Subtended angle"
b) Draw a triangle with two sides equal to the info above.
c) Check your answer isn't out by a factor of 2.
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| User: "Randy Poe" |
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| Title: Re: Basic physics question. |
27 Jan 2005 02:27:10 PM |
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wrote:
I have this homework problem that I can't figure out what it is
asking... the book never even mentions anything remotely related to
this.
Are you sure? You never for instance saw the relationship
between angle subtended and arc-length: d = R*theta?
I'm not asking for the answer, but just am trying to find out what to
do with the problem.
Any Help?? Thanks in advance.
Consider the following accepted constants:
Radius of the moon = 1.74e6 m.
Radius of the sun = 6.96e8 m.
Average moon-earth distance = 3.84e8 m.
Average sun-earth distance = 1.496e11 m.
a) What is the apparent angle the diameter
of the moon subtends, as seen from the earth,
in radians?
In the above relationship d = R*theta, R is the
radial distance to the distant object, d is the
arc length in meters from one side of the object
to the other (Note: You're given the radius, which
is not that distance), theta is the angle you want.
With these very small angles the arc length across
the moon and the straight-line distance across the
moon are essentially the same.
- Randy
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| User: "" |
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| Title: Re: Basic physics question. |
27 Jan 2005 02:09:00 PM |
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wrote:
I have this homework problem that I can't figure out what it is
asking... the book never even mentions anything remotely related to
this.
I'm not asking for the answer, but just am trying to find out what to
do with the problem.
Any Help?? Thanks in advance.
Consider the following accepted constants:
Radius of the moon = 1.74e6 m.
Radius of the sun = 6.96e8 m.
Average moon-earth distance = 3.84e8 m.
Average sun-earth distance = 1.496e11 m.
a) What is the apparent angle the diameter
of the moon subtends, as seen from the earth,
in radians?
It is a trig problem.
Imagine your eye at one corner of a triangle; I'll leave the rest up to
you.
--
Jim Pennino
Remove -spam-sux to reply.
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| User: "PD" |
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| Title: Re: Basic physics question. |
27 Jan 2005 04:17:23 PM |
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I'll give you a hint.
Your thumb, at arm's distance subtends about the same angle, which you
can check tonight (or actually tomorrow morning) by blotting the moon
out with your thumb.
So standing there, draw a line from your eye to the right side of your
thumb to the right side of the moon, and repeat for the left side of
thumb and moon. Now look at your drawing.
PD
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