When you look at the sun from earth, you have no trouble discerning its circular

Question

When you look at the sun from earth, you have no trouble discerning its circular shape. The sun is 1.4*10^9 meters in diameter, and is 1.5*10^11 meters away. If you were standing on Pluto, however, (and we ignore that your eyeballs would freeze, you couldn't breathe, and indeed if your lungs were full of air, you would instantly explode without a pressurized space suit.) the sun would look very different. Pluto is about 40 times as far from the sun as the Earth is. Could you still image the sun on your retina (ie image greater than 2 microns), or would it just be a twinkling bright but shapeless entity like a far away star?

show your calculations

Explanation / Answer

As we know that the lens equation
(1/di)+(1/do) = 1/f
Where di is the image distance, do is the object distance and f is the focal length
so
1/di = (1/f) - (1/do)
di = dof / (do-f)
f for eye is 1.7 cm
di = 0.017 m
On changing the distance to 40 times the image will remain at focus
And we know from
magnification (m) = I/O = -di/do
Where I is height of image or image size , O is the object size
When distance is 40 times
So I = (di/do)O = 1.5867*10-4
so on increasing the value of do
the size of the image dimnished .
I' = I/40 = 3.967*10-6 m
which is greater than 2 micron.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.