Which of these locations on earth experiences at least change in the number of daylight hours throughout the year?
a) north pole
b) terrestrial equator
c) tropic of capricorn
d) tropic of cancer
e) south pole

the working equation for the angular size is the product of the physical size and 360 degrees divided by the product of two pi and distance from earth. the minimum size would be 0.559 degrees while the maximum size would be 0.49 degrees. 

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.