varies directly as the product of their masses (M kg and m kg), and inversely as
the square of the distance ( d m ) between the two objects. If the mass of each
of the two objects increases by 100% and the distance between them decreases
by 50%, how many times will the new gravitational force be as large as the
original?
更新1:
唔明點計到16
更新2:
OK明了..................