A mass `m` is taken to a height `R` from the surface of the earth and then is given a vertical velocity `upsilon`. Find the minimum value of `upsilon`, so that mass never returns to the surface of the earth. (Radius of earth is `R` and mass of the earth `m`).

Explanation

Using the equation
`K_(i) + U_(i) = K_(f) + U_(f)`
`:. (1)/(2) m nu^(2) - (GmM)/(2R) = 0 + 0`
`:. Nu = sqrt((GM)/(R))`