Answer:Three times
Explanation:
The change in the energy of pile driver-Earth system is given by change in Potential energy
Potential energy is given by
[tex]P.E.=mgh[/tex]
where m=mass of object
g=acceleration due to gravity
h=height from which object is dropped
When mass of object being dropped is tripled then Potential energy is tripled
i.e. [tex]P.E.=3\times mgh[/tex]
Thus energy is multiplied by a factor of 3
