The wheels and gears of a machine are greased in order to decrease
1 2 3 4
potential energy efficiency output friction
Question: The wheels and gears of a machine are greased in order to decrease
(1) potential energy
(2) efficiency
(3) output
(4) friction

Answer: (4) friction
Answer: (3) output
Question: The wheels and gears of a machine are greased in order to decrease
(1) potential energy
(2) efficiency
(3) output
(4) friction
Answer: (4) friction