# physics-telescope

The Hubble Space Telescope (HST) can resolve objects that have a small
angular separation because there is no atmospheric distortion of the light. (i.e. The HST has excellent
resolving power.) Its 2.4-m-diameter primary mirror can collect light from distant galaxies that
formed early in the history of the universe. How far apart can two galaxies be from each other if they
are 10 billion light-years away from Earth and are barely resolved by the HST using visible light with
a wavelength of 400 nm? You may assume that the aperture diameter is the full 2.4 m diameter of the
mirror.

okay so this is what I have tried so far:
I used a sin delta theta>/= 1.22 lambda nought
rearrange to get
delta theta>/= [inverse sin (1.22)(4.00*10^-9m)]/2.4m
so delta theta = 0.00001165

The only reason I used that formula is because it seemed like the best option. I'm not even sure if I'm using the right one.

I don't even know if I'm on the right track, and I have no idea what to do from here. Any help would be appreciated!

1. 👍 0
2. 👎 0
3. 👁 184
1. You are on the right track but do not appear to be solving for the separation distance of the galaxies from each other. Call that x. That is what they are asking for.

1.22 (lambda)/D = x/R

where R is 10 million light years
lambda = 400*10^-9 m
D = 2.4 m

Solve for x.
If you leave both x and R in light years, you can solve for x in light years.
x/R = 2.03*10^-7 (a dimensionless ratio)
x = 203 light years (when the light was emitted 10 billion light years ago)

1. 👍 0
2. 👎 0
2. My prof says that the answer should be of magnitude 10^19. I'm not sure what he's doing differently. Is there another way to solve this?

1. 👍 0
2. 👎 0
3. I tried to get help from a friend, but her email just said to use tan theta = x/D. I'm not sure why she said to use tan theta, and when I do that-> tan 0.00001165*2.4m=x I get x= 0.000000487 which is obviously not right.

1. 👍 0
2. 👎 0

## Similar Questions

1. ### astronomy

In space, the angular resolution of the Keck telescope is govererned by the diffraction limit. How far away could you read the same book, using the Keck telescope in space? Please express your answers in units of meters.

2. ### astronomy

The Keck telescope on Mauna Kea has an angular resolution on Earth of half an arcsecond. How far away (in meters) could you read ("resolve the letters of") a book with 3 mm square type, using the Keck telescope on Earth?

3. ### Astronomy

When used at a wavelength of 1 micron, a telescope can resolve angles as small as 0.1 seconds of arc. How small an angle could the telescope resolve when used at a wavelength of 5 microns? a. 0.02 seconds of arc b. 0.004 seconds

4. ### Art

Three Pears By Paul Cézanne 1. Which of the following statements is not true? A. The pears occupy the positive space in this image. B. Recognizing the negative and positive spaces could have made it easier for the artist to paint

1. ### Astronomy

The Hubble Space Telescope orbits at an altitude of 600 km above the Earth's surface. Assuming it is in a stable circular orbit, what is its velocity? For reference, the Earth's radius is 6400 km and Earth's mass is 6 x 10^24 kg.

2. ### astronomy

Which of the following two telescopes has a better angular resolution? 1) the Hubble Space Telescope (2.4 meter aperture) at optical wavelengths and 2) the Very Long Baseline Array (VLBA), a radio interferometer with a maximum

3. ### astronomy

Which of the following two telescopes has a better angular resolution? 1) the Hubble Space Telescope (2.4 meter aperture) at optical wavelengths and 2) the Very Long Baseline Array (VLBA), a radio interferometer with a maximum

4. ### astronomy

The Keck telescope on Mauna Kea has an angular resolution on Earth of half an arcsecond. How far away (in meters) could you read ("resolve the letters of") a book with 3 mm square type, using the Keck telescope on Earth?

1. ### Physics

On earth, two parts of a space probe weigh 18300 N and 4440 N. These parts are separated by a center-to-center distance of 5.11 m and may be treated as uniform spherical objects. Find the magnitude of the gravitational force that

2. ### PHYSICS--

The objective and eyepiece of an astronomical telescope are double convex lenses with refractive index 1.5. When the telescope is adjusted to infinity, the separation between the two lenses is 16 cm. If the space between the

3. ### Physics

The space shuttle releases a space telescope into orbit around the earth. The telescope is traveling at a speed of 1700m/s in 25 seconds. What is the distance of the satellite? d = v x t d = 1700 x 25 = Is that the correct

4. ### Covenant polytechnic. Aba.

Two converging lenses having power of +2.0 and +20.0 diopter are used to give magnifications in an astronomical telescope. calculate the angular magnification of the telescope when (I).in normal adjustment. (ii).The final image is