A satellite of mass m is at a distance a from a star of mass M. the speed of satellite is `u`. Suppose the low of universal gravity is `F=-G(Mm)/(r^(2.1))` instead of `F=-G(Mm)/(r^(2))` find the speed of the statellite when it is at a distance b from the star.

Options

A. `sqrt(u^(2)+2GM((1)/(b^(1.1))-(1)/(a^(1.1))))`
B. `sqrt(u^(2)+GM((1)/(a^(1.1))-(1)/(b^(1.1))))`
C. `sqrt(u^(2)+(2)/(1.1)GM((1)/(b^(1.1))-(1)/(a^(1.1))))`
D. `sqrt(u^(2)+(2)/(2.1)GM((1)/(b^(1.1))-(1)/(a^(1.1))))`

Answer

C

Explanation

`F=-(GMm)/(r^(2.1))impliesmv(dv)/(dr)=-(GMm)/(r^(2.1))`
`int_(u)^(v)vdv=-Gmmint_(a)^(b)(1)/(r^(2.1))dr`