Answer:
The new kinetic energy is 9 times of the initial kinetic energy.
Step-by-step explanation:
The kinetic energy of an object is given by the formula as follows :

Where
m is mass and v is speed of the body
If the speed of the body is tripled. Let v' is the new speed, v' = 3v. The new kinetic energy is E' and it is given by :

Hence, the new kinetic energy is 9 times of the initial kinetic energy.