Question

A pulley system has five pulleys in all and is 90% efficient such that it lifts a load of 1000 N. Answer the following question:

The mechanical advantage of the pulley system is:

Options

• 4.50

• 4.45

• 4.40

• 4.55

Answer 1

4.50

Explanation:

Given:

Total number of pulleys (n) = 5

Therefore, Velocity Ratio (VR) = 5

Efficiency (η) = 90% = 0.90

Load (L) = 1000 N

Formula:

\[ \text{Efficiency } (\eta) = \dfrac{\text{Mechanical Advantage (MA)}}{\text{Velocity Ratio (VR)}} \]

MA = η × VR

= 0.90 × 5

= 4.50