- #1

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## Main Question or Discussion Point

I wonderd how if could calculate G the gravitational constant by combining the two formulas;

Fg=G x (m1 x m2 / r^2)

Fz=m1 x g

you can only make these two fromulas equal to each other when you stand on the surface of the earth. or when you recalculate your g (accelaration towards the mass).

m1= your mass

m2= mass of the earth

R= the radius of the earth

G= the gravitational constant

g= the gravitional accelarationon the surface of the earth in 9.81 m/s^2

m1xg = G x (m1 x m2 / r^2)

g = G x (m2 / r^2)

so from here out you can say that

G = (g x R^2)/m2

this is correct.

but now when I take g what is an accelaration in s/t^2

s= travelled distance

t= time

and put it in this formula you wil get..

G = (2s x R^2)/(t^2 x m2)

supposedly you take s=1

then you can calculate your time with the accelaration formula s=0.5 x g x t^2

and so you can calculate the correct G constant,

but assuming you're standing on the surface of the earth your s (travelled distance) is actually 0 so your time is also 0 and that makes G also 0. Why because you do not move in space towards the mass of the earth, you actually do not travel any distance, if you would jump up a metre then you would have a distance to travel towards earth. giving you a time and so being able to calculate G.

can someone explain me what I did wrong because sofar nobody could answer me the question

Fg=G x (m1 x m2 / r^2)

Fz=m1 x g

you can only make these two fromulas equal to each other when you stand on the surface of the earth. or when you recalculate your g (accelaration towards the mass).

m1= your mass

m2= mass of the earth

R= the radius of the earth

G= the gravitational constant

g= the gravitional accelarationon the surface of the earth in 9.81 m/s^2

m1xg = G x (m1 x m2 / r^2)

g = G x (m2 / r^2)

so from here out you can say that

G = (g x R^2)/m2

this is correct.

but now when I take g what is an accelaration in s/t^2

s= travelled distance

t= time

and put it in this formula you wil get..

G = (2s x R^2)/(t^2 x m2)

supposedly you take s=1

then you can calculate your time with the accelaration formula s=0.5 x g x t^2

and so you can calculate the correct G constant,

but assuming you're standing on the surface of the earth your s (travelled distance) is actually 0 so your time is also 0 and that makes G also 0. Why because you do not move in space towards the mass of the earth, you actually do not travel any distance, if you would jump up a metre then you would have a distance to travel towards earth. giving you a time and so being able to calculate G.

can someone explain me what I did wrong because sofar nobody could answer me the question