Respuesta :

Ek = 0.5 * m * v^2 

Ek = kinetic energy (in Joules) 
m = mass (in kg) 
v = velocity (in m/s) 

Solving: 
Ek = 0.5 * 10 kg * 3 m/s^2 
Ek = 45 Joules <--------- answer.