have a surface contact when in motion

have a line or point contact when in motion

are kept in contact by the action of external forces, when in motion

permit relative motion

difference between the maximum and minimum energies

sum of the maximum and minimum energies

variations of energy above and below the mean resisting torque line

ratio of the mean resisting torque to the workdone per cycle

structure

machine

inversion

compound mechanism

piston, piston rod and crosshead

connecting rod with big and small end brasses, caps and bolts

crank pin, crankshaft and flywheel

all of the above

0 Degree and 90 Degree

180 Degree and 360 Degree

0 Degree and 90 Degree also 180 Degree and 360 Degree

none of these