What is the proper defination of Mechanical Advantage of an idel machine?

Answer 1

#In physics and engineering, mechanical advantage (MA) is the factor by which a mechanism multiplies the force put into it. Following are simple machines where the mechanical advantage is calculated.

#There are two types of mechanical advantage:

1.Ideal mechanical advantage (IMA)
2.Actual mechanical advantage (AMA)

#Ideal mechanical advantage:

The ideal mechanical advantage is the mechanical advantage of an ideal machine. It is usually calculated using physics principles because there is no ideal machine. It is 'theoretical.'

The IMA of a machine can be found with the following formula:

IMA=DE /DR

where,

DE equals the effort distance
DR equals the resistance distance.

http://en.wikipedia.org/wiki/Ideal_mechanical_advantage

Answer 2

Let us first assume a simple lifting machine,
for which:

P= effort applied to lift the load
W= Load lifted by the machine
D= Distance moved by effort to lift the load
d = Distance moved by load
M.A. = Mechanical Advantage
V.R. = Velocity Ratio

Now, M.A. = W/P
V.R. = D/d

Now input = work done by effort = P*D
output= work done by load = W*d


efficiency of machine n = output/input

= W*d/P*D

= (W/P)/(D/d)

= M.A./V.R.

Now for ideal machine there will be no loss due to friction, so here,

output= input

As n= output/input = 1

efficiency of an ideal machine is 100%.

so, for ideal machine,

1= M.A/V.R.
M.A. = V.R.

therefore for ideal machine, Mechanical Advantage is equal to it's Velocity Ratio.

Answer 3

It is the ratio of the force that is output compared to the force that is input.