Answer:
12J
Step-by-step explanation:
Given parameters: 
Mass = 1.5kg 
Impulse = 6kgm/s 
 let us start first by find the velocity with which this body moves; 
 Impulse = mass x velocity 
 Velocity = Impulse / mass = 6/ 1.5 = 4m/s 
Initial velocity = 0m/s 
Unknown: 
Resulting kinetic energy = ? 
Solution: 
To solve this problem use the formula below: 
 K.E = 
 m (v - u)²
 m (v - u)² 
m is the mass 
v is the final velocity 
u is the initial velocity 
 So; 
 K.E = 
 x 1.5 x (4 - 0)²
 x 1.5 x (4 - 0)² 
 K.E = 1.5 x 8 = 12J