## Homework Statement

A washing machine that weighs 1400N must be put into a delivery truck bed that is 1.2 m off the ground. A worker uses a force of 450N to push the machine up a ramp that is 4.3m long. What is the efficiency of the inclined plane?

## Homework Equations

e=(MA/IMA)100---- efficiency of a machien in % is = to its mechanical advantage, divided by the ideal mechanical advantage, multiplied by 100.
MA=Fr/Fe---- mechanical advantage=the resistance of force divided by the effort force.
IMA=De/Dr----the ideal mechanical advantage of an ideal machien is=to the displacement of the effort force, divided by the displacement of the load.

## The Attempt at a Solution

MA=1400N/450N=3.11N, I think i did that part right.
IMA=1.2m/4.3m=0.28m, I think i did this part wrong.
e=(3.11N/0.28m)100=1110.71joules.

Last edited:

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rl.bhat
Homework Helper
Hi Jonathan Teas, welcome to PF.
First of all MA or IMA are pure numbers. No units for them.
Next IMA = Distance traveled by effort/ distance traveled load. = ...?
In Ist or second type of machine IMA cannot be less than one.

Hi Jonathan Teas, welcome to PF.
First of all MA or IMA are pure numbers. No units for them.
Next IMA = Distance traveled by effort/ distance traveled load. = ...?
In Ist or second type of machine IMA cannot be less than one.
If IMA= Distance traveled by effort/ distance traveled load
then IMA= 4.3m/1.2m=3.58 then no unit?
so the answer is 3.11no unit again/3.58=(0.87)100=87%
Thank you very much.