Unit 1- Planet Earth Flashcards
1
Q
What is the mean diameter of the Earth?
A
13000km
2
Q
How many minutes is 1 degree?
A
60 minutes
3
Q
How did Eratosthenes determine the circumference of the Earth?
A
During the summer solstice, the Sun would be at its zenith at noon over Syene. He did the same in Alexandria, measuring a shadow of 7.2 degrees. Then, he found the difference between the 2 places (around 800km or 5000 stadia) and did simple maths to figure out the circumference.
7.2 degrees/ 360 = 800km/ X km
1/50 = 800/ X km
50*800= 40,000km
X= 40,000km
4
Q
When is the summer solstice?
A
July 21st
5
Q
How long is a solar month?
A
29.5 days
6
Q
HOW LONG IS A LUNAR MONTH?
A
27.3 days
