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ANALYSIS TO SIMPLE

MACHINEThe castings must be lifted 200 mm

FORCE MULTIPLIER RATIO (MECHANICAL ADVANTAGE)

In the lever system shown in figure 4 above, the load being lifted is about

three times more than the effort being applied. The load divided by the effort

gives a ratio. This ratio is a force multiplier, or how much more load can belifted compared to the effort.

The lever in figure therefore has a force-multiplier ratio of 2.88 a ratio has no

units of value!.

. EFFORT = 260 N

LOAD = 750 N

600 mm

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ANALYSIS TO SIMPLE

MACHINE

Example 1

"ind the force-multiplier ratio for the lever in figure above.

"orce-multiplier ratio # load

effort

# $%0 &

2'0 &

# 2.88

EFFORT = 260 N

LOAD = 750 N

600 mm

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ANALYSIS TO SIMPLE

MACHINE

"ind the distance-multiplier ratio leverage for the lever in figure 4 above.

(ovement-multiplier ratio # distance moved by the effort

distance moved by the load

# '00 mm

200 mm

# )

EFFORT = 260 N

LOAD = 750 N

600 mm

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ANALYSIS TO SIMPLE

MACHINEExample

"ind the efficiency of the lever system shown in figure 4.

*fficiency +! # "orce atio 00

(ovement atio

+ # 2.88 00 + # '% )

The system shown in figure has an efficiency of nearly 00 per cent. &o

system can be 00 per cent efficient/ there are always losses. The losses in a

lever system consist of energy lost to friction at the fulcrum of the lever andthe energy lost in strain as the lever bends slightly. In some cases a small

amount of energy will also be lost in the form of sound.

Remember, no machine i !"" #er cen$ e%%icien$& Common

ener' oe inc*+e hea$ ener' +*e $o %ric$ion, $rainener an+ o*n+ ener &