Question

You are an astronomer on planet Nearth, which orbits a distant star. It has recently been accepted that Nearth is spherical in shape, though no one knows its size. One day, while studying in the library of Alectown, you learn that on the equinox your sun is directly overhead in the city of Nyene, located 1000 kilometers due north of you. On the equinox, you go outside in Alectown and observe that the altitude of your sun is T77°

Answer 1

circumference of Nearth = 27692.30 km

Step-by-step explanation:

we will apply here Eratosthenes logic that is here in this problem

near the sun is straight overhead at nyene and at same time that is ( 90-77 ) = 13° from zenith at the Alec town

and here 2 city 1000 km apart

so by Eratosthenes relation is

1000 =
`(13)/(360)` × circumference of Nearth

circumference of Nearth = 1000 ×
`(360)/(13)`

circumference of Nearth = 27692.30 km