The earth-moon distance is about 60 earth radius. What will be the diameter of the earth (approximately in degrees) as seen from the moon ?

The earth-moon distance is about 60 earth radius. What will be the dia

1.	The earth-moon distance is about 60 earth radius. What will be the diameter of the earth (approximately in degrees) as seen from the moon ?
Answer» Solution :Angle subtended at distance r due to an arc of LENGTH 1 is `theta=(l)/(r)` Given `l=R_(e), r=600 R_(e)` `theta=(R_(e))/(60R_(e))=(1)/(60) "rad" = (1)/(60)XX(180^(@))/(pi)` `:. theta=(3)/(pi)=1^(@)` Thus, angle subtended by diameter of the EARTH `=2 theta=2^(@)`.