Question

HELP ASAPPP !!!!!

In a closed system that has 85 J of mechanical energy, the gravitational
potential energy of a weight being lowered by a pulley decreases from 12 J to
9 J. How does the system's kinetic energy change if there is no friction?
OA. It increases from 85 J to 94 J.
B. It decreases from 85 J to 76 J.
C. It decreases from 76 J to 73 J.
OD. It increases from 73 J to 76 J.

Answer 1

In a closed system with no friction, the system's kinetic energy will increase from 85 J to 94 J as the gravitational potential energy decreases from 12 J to 9 J.

Step-by-step explanation:

In a closed system, the mechanical energy remains constant. The mechanical energy is the sum of the gravitational potential energy and kinetic energy. According to the Law of Conservation of Mechanical Energy, the total mechanical energy will not change if there are no external dissipative forces acting on the system.

In this case, the gravitational potential energy decreases from 12 J to 9 J. Therefore, the kinetic energy of the system will increase to compensate for this decrease, resulting in an increase in the system's kinetic energy from 85 J to 94 J.