Sunlight passing through a pinhole in a piece of card casts a solar image on the ground. If the card is held so the image exactly covers a coin, measurements will show you could fit 110 coins between the image and the card. This further tells you
A)110 Suns would fit between the top of the card and the Sun.
B)that this activity is useful for estimating the Sun's diameter.
C)both of these
D)neither of these

Question

Quizplus · Accepted Answer

This activity demonstrates a simple method of estimating distances and sizes in astronomy, using similar triangles. If the solar image exactly covers a coin and you could fit 110 coins between the image and the card, it means the ratio of the Sun's diameter to the distance from the Earth to the Sun is the same as the coin's diameter to the distance from the coin to the card. Therefore, both A and B are correct: 110 Suns would fit between the Earth and the Sun, and this activity is indeed useful for estimating the Sun's diameter.

Sunlight Passing Through a Pinhole in a Piece of Card