# An object weighs 200 N on Earths surface. When it is moved to a point one Earth radius above earths surface it?

will weigh:

A. 25. N

B. 50. N

C. 100. N

D. 400. N

Relevance

200 N. It still weighs 200 N.

It might be, however, easier to move around that that altitude, given the lesser effects of gravity.

Oh, and what HARRINGTON said. Good one.. Complicated for those of us are the non-physics types, but good nonetheless.

• The object Weight is given with 2 formulas:

W= m g and

W= g M m / r² from this formula we find the earth mass :

M = W r² / g m

Where r is the distance of the object from the center of the earth when it is on the ground and is equal to r

When the object is at height r from the ground we have obejct distance from center of the earth to the object will be r+r = 2r

So Wr at height r is:

Wr= g Mm / (2r)² so if we take M from the 2nd formula we have

Wr = g W r² m / gm (2r)²

= W r² / 4 r²

= W /4 = 200 / 4 = 50 N

• Anonymous
9 years ago

B. 50 N

This is because the square of the distance is inversely proportional to the weight of an object.

1/d^2= weight

So if distance doubles, (because it is moved one Earth radius above the surface), you divide the weight by 2 squared, which is 4.

200N/4= 50N

• Anonymous
9 years ago

50 N

F=G*me*mo/r^2

derive to acceleration

A=G*M/r^2

F=force

A=acceleration

G=6.67E-11 N*m^2/kg^2

M=5.98E24 kg

r=63781000 m

Source(s): AP Physics