Answer to Question #137662 in Mechanics | Relativity for Mujib Ahmed

Question

A machine having a V.R 4 needs 2000J of energy to left a load of 400N through a perpendicular distance of 2.5m.Calculate
A.efficiency
B.M.A

Answer 1

Solution

Given data

Velocity ratio (VR)=4

Load(L)=400N

Distance moved by load=2.5 m

According to velocty ratio

$VR=\frac{displacement\space of\space effort}{displacement\space of\space load}$

So by putting the value

$4=\frac{displacement\space of \space effort}{2.5}$

so

Displacement of effort =$4\times 2.5$

=10 m

And

Work done by Effort=Effort.displacement of Effort

By putting the value

$2000=Effort\cdot10\\Effort=\frac{2000}{10}=200 N$

And

(B)

$MA=\frac{load(L)}{effort(E)}\\MA=\frac{400}{200}=2$

$MA=2$

(A)

$Efficiency=\frac{MA}{VR}$

by putting the value

$Efficiency (\eta)=\frac{2}{4}=\frac{1}{2}$

So

$\eta=50$ %

So Mechanical advantage is 2 and efficiency is 50%.