Aperson who weighs 800n on the earths surface will weigh 200n at what height above the earth

6,400 km

Explanation:

The weight of a person is given by:

where m is the mass of the person and g is the acceleration due to gravity. While the mass does not depend on the height above the surface, the value of g does, following the formula:

where

G is the gravitational constant

M is the Earth's mass

r is the distance of the person from the Earth's center

The problem says that the person weighs 800 N at the Earth's surface, so when r=R (Earth's radius):

(1)

Now we want to find the height h above the surface at which the weight of the man is 200 N:

(2)

If we divide eq.(1) by eq.(2), we get

By solving the equation, we find:

which has two solutions:

--> negative solution, we can ignore it

--> this is our solution

Since the Earth's radius is , the person should be at above Earth's surface.

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.