in a closed system that has 85 J of mechanical energy the gravitational potential energy of a weight being lowered by pulley decreases from 12 J to 9 J. How does the systems kinetic energy change if there is no friction

The human activities in two locations are described below: location a: rampant use of plastic containers location b: excessive use of pesticides and fertilizers which statement is most likely true? location a will have poor air quality because plastic is biodegradable. location a will experience water scarcity because plastic absorbs moisture. the population of honeybees will increase in location b because production of crops will increase. the population of fish in location b will decrease because the water is contaminated.