Simple problem i need help with

  • Thread starter k_yup
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  • #1
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im new to the physics world and know this is probably an easy problem but i dont know where to start

Hold a pencil in front of your eye at a position where its end just blocks out the moon. Make approprite measurements to estimate the diameter of the moon, given that the earth-moon distance is 3.8x10^5km.

i figured that you prob had to measure the end of a pencil which i measured about 1.5 cm which is 1.5x10^-5km but i dont really know what to do from there.
 

Answers and Replies

  • #2
LowlyPion
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im new to the physics world and know this is probably an easy problem but i dont know where to start

Hold a pencil in front of your eye at a position where its end just blocks out the moon. Make approprite measurements to estimate the diameter of the moon, given that the earth-moon distance is 3.8x10^5km.

i figured that you prob had to measure the end of a pencil which i measured about 1.5 cm which is 1.5x10^-5km but i dont really know what to do from there.

How far away was the pencil from your eye?
 
  • #3
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about 15cm
 
  • #4
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so use simular triangle theory?
 
  • #5
LowlyPion
Homework Helper
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so use simular triangle theory?

Yes, that would do it nicely.

Sorry for late reply I guess I missed it last night when I scanned the board.

Good luck.
 

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