Estimate Earth's Radius Using Sun's Disappearance Time

[crazyforfood]

The Sun sets, fully disappearing over the horizon as you lie on the beach, your eyes 20 cm above the sand. You immediately jump up, your eyes now 170 cm above the sand, and you can again see the top of the Sun. If you count the number of seconds until the Sun fully disappears again, you can estimate the radius of the Earth. Use the known radius of the Earth to calculate the time.

 

[Sakha]

If this is your homework, then you could first give some of the ideas you have and we help you.

 

[crazyforfood]

i don't have any! confused