Answer:
4 Joules.
Step-by-step explanation:
In a mechanical system, the total energy is the sum of the potential energy and kinetic energy. Mathematically, it can be represented as:
Total Energy (TE) = Potential Energy (PE) + Kinetic Energy (KE)
In your case, you have the total energy (TE) as 12 J and potential energy (PE) as 8 J. To find the kinetic energy (KE), you can use the formula:
KE = TE - PE
Substitute the given values:
KE = 12 J - 8 J = 4 J
So, the kinetic energy in the system is 4 Joules.