Question

A machine can lift a useful load of 80 kgf and effort E. If the efficiency of machine is 80% and velocity ratio 5, calculate:

1. Actual mechanical advantage.
2. The value of effort E.

Answer 1

Given: Useful load (L) = 80 kgf

Efficiency (η) = 80% = 0.8

Velocity ratio (VR) = 5

Formula: η = `"MA"/"VR"`

a. Actual mechanical advantage: MA = η × VR

MA = 0.8 × 5

= 4

b. MA = `"L"/"E"`

E = `"L"/"MA"`

= `80/4`

= 20 kgf