Simple Machines

Simple machines:• Reduce the effort (force multiplier)

Simple machines:• Reduce the effort (force multiplier)

• Change point of application of effort to a convenient point

Simple machines:• Reduce the effort (force multiplier)

• Change point of application of effort to a convenient point

• Change the direction of effort

Simple machines:• Reduce the effort (force multiplier)

• Change point of application of effort to a convenient point

• Change the direction of effort

• Produce a gain in speed

Simple machines:• Reduce the effort (force multiplier)

• Change point of application of effort to a convenient point

• Change the direction of effort

• Produce a gain in speed

• Load

• Effort

• Mechanical advantage, M.A. = Load (L)Effort (E)

L > E - M.A. > 1 – force multiplierE > L - M.A. < 1 – gain in speedE = L - M.A. = 1 – changes direction of effort

(no change in force/speed)

Units

Technical terms

• Velocity ratio, V.R. = Velocity of effort (VE)Velocity of load (VL)

V.R. = dE/t

dL/t

V.R. = dE

dL

dE > dL – V.R. > 1 – force multiplierdL > dE – V.R. < 1 – gain in speeddL = dE – V.R. = 1 – changes direction of effort

(no change in force/speed)Units

Technical terms

Technical terms• Work input• Work output

MachineEffort LoadWork input

Work output

Technical terms• Work input• Work output

MachineEffort LoadWork input

Work output

Technical terms• Work input• Work output

MachineEffort Load

Work input

Work output

Technical terms• Work input• Work output

MachineEffort Load

Work input

Work outputEfficiency, η =

Technical terms• Work input• Work output

MachineEffort Load

Work input

Work outputEfficiency, η =

Units

Technical terms• Effort point• Load point• Input energy• Output energy• Principle of a machine• Relation between M.A., V.R. and η