They are a variable that changes as a result of the changes in the manipulated variable
Answer:
U = 102.8 J (100 J to two significant digits)
Explanation:
potential energy converted = 20(9.8)(1.8) = 352.8 J
kinetic energy at base of track = ½(20)5.0² = 250 J
energy (work) of friction 352.8 - 250 = 102.8 J
The way the sound waves hit your eardrums and they are moved by the sound pressure. Then your brain takes over from there.