For small heights (with )

PHYSICS · Single correct · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

For small heights

h

(with

h \ll R

), which of the following expressions correctly gives the acceleration due to gravity

g_h

at height

h

above Earth’s surface? (Here

g

is the surface value and

R

is Earth’s radius.) (a)

g_h = g\left(1 - \dfrac{h}{R}\right)

(b)

g_h = g\left(1 - \dfrac{h}{2R}\right)

(c)

g_h = g\left(1 - 2\dfrac{h}{R}\right)

(d)

g_h = g\left(1 - \dfrac{3h}{2R}\right)