The formula for kinetic energy is KE = 1/2 mv^2 or kinetic energy is equal to half of mass times velocity squared.
Our mass is 12,000 kg
Our velocity is 30 m/s
So In the formula it would be
KE = 1/2 12,000kg * 30 m/s^2
First square the velocity to make it 900.
Then multiply that by 12,000 which will equal 10,800,000, then divide that by 1/2 which is equal to 5,400,000 Joules or J
Your answer is likely to be 5,400,000 J
I apologize if anything is wrong and please ask me if you have any questions.