spacetimedude
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Homework Statement
Consider the position vector of a mass m at height h above the Earth's surface to be \underline{r}=(R+h)\underline{e}_z where R is the radius of the Earth.
Make a Tylor expansion in h/R <<1 of the gravitational field
\underline{G}(\underline{r})=\frac{-GM\underline{r}}{r^3}
to show that the gravitational force on a mass m can be written as \underline{F} \approx mg\underline{e}_z giving an expression for g in terms of R and M, the mass of the Earth.
Find the first correction (h-dependent) to the gravitational force.
Homework Equations
The Attempt at a Solution
I am having trouble understanding how to expand the function in h/R<<1.
We can rewrite \underline{G}(\underline{r})=\frac{-GM(R+h)}{(R+h)^3}\underline{e}_z which then can then be expressed as \underline{G}(\underline{r})=\frac{-GM}{R^2}(\frac{h}{R}+1)^{-2}\underline{e}_z
I am not sure how to proceed with the expansion.
Any explanation will be appreciated.