Question

To what fraction of its current radius would Earth have to shrink( with no change in mass) for the gravitational acceleration at its surface to triple?

Answer 1

Do you know the expression for the gravitational acceleration?!

Answer 2

yes it is \[g=\frac{ GM }{ R ^{2} }\]

Answer 3

ok..

so now the acceleration has to beocme 3g.. so calcuate the new R