Answer:
153760000 J 
Step-by-step explanation:
Kinetic energy is the energy possessed by a moving object solely due to its motion. 
 You can get the K.E. of an object using the equation, 
 K.E. = (1/2)mv² 
 So you get, for submarine,
K.E. = (1/2)×8000000×6.2²
 = 153760000 J = 0.153 GJ