Question

C Numerical Problems
1. An effort of 45 N is applied on a machine through a
displacement of 8 m. As a result of it, a load of 270 N is
moved through a distance of 10 m Calculate velocity
ratio, mechanical advantage and efficiency of the
machine
​

Answer 1

Given:

F1 = 45 N

d1 = 8 m

F2 = 270 N

d2 = 10 m

To find:

1) velocity ratio = VR =?

2) mechanical advantage = M.A. =?

3) efficiency of the machine = η =?

Explanation:

1)

The velocity ratio is the ratio of a distance through which any part of a machine moves to that the driving part moves during the same time.

$\displaystyle Velocity \ ratio = \frac{distance \ of \ effort}{distance \ moved \ by \ load}$

VR = $\frac{8}{10}$

VR = 0.8

2)

The mechanical advantage the ratio of the force produced by a machine to the force applied to it, utilized in assessing the performance of a machine.

M.A. = $\displaystyle \frac{Load}{Effect}$

       = $\displaystyle \frac{270}{45}$

M.A. = 6

3)

The efficiency of the machine is that the percent of work put into a machine by the input work that becomes work done by the machine output work.

$\displaystyle \eta =\frac{mechanical \ \ advantage}{velocity\ \ ratio}$

  = $\displaystyle {\frac{0.8}{6}{ \times 100}$

η = 13.33 %