Question

An effort of 500 N is applied through a distance of 0.50 m on a machine, whose efficiency is 90%, such that resistance is overcome through a distance of 0.04 m. Calculate the (a) V.R. (b) M.A. (c) resistance overcome by the machine.

Answer 1

(a) Velocity ratio \[= \frac{\text{Distance moved by effort}}{\text{Distance moved by resistance}} \]

\[= \frac{0.50\ \text{m}}{0.04\ \text{m}} \]

\[= 12.5 \]

(b) Mechanical advantage

\[ \eta = \frac{\text{MA}}{\text{VR}} \]

\[ \therefore \text{MA} = \eta \times \text{VR} \]

\[ \text{MA} = 0.90 \times 12.5 \]

\[ \text{MA} = 11.25 \]

(c) Resistance:

\[ \text{MA} = \frac{\text{Resistance}}{\text{Effort}} \]

\[ \therefore \text{Resistance} = \text{MA} \times \text{Effort} \]

\[ \text{Resistance} = 11.25 \times 500\ \text{N} \]

\[ \text{Resistance} = 5625\ \text{N} \]