Answer:
F= 25/2 = 12.5N
Explanation:
When you use a compound pulley the force required depends on the mechanical advantage of the compound pulley. This is known as rate of loss of distance or the ratio of the force to the load.
M.A = Effort distance /Load distance. OR M.A = Load/Effort
Very specific alignment of the Sun, Earth, and Moon. If the Moon is lined up precisely with the Sun from the Earth's point of view, the Moon will block Sunlight from reaching the Earth, causing a solar eclipse.
Earths atmosphere, Temperature, Plant life and Oxygen I guess