Question

Show a neat diagram to explain the working of a single fixed pulley. Calculate the mechanical advantage and velocity ratio for this pulley.

Answer 1

Calculation of Mechanical Advantage (MA):

In an ideal equilibrium position, the tension (T) acts upwards on both sides of the string.

The load (L) is directly supported by the tension (T) in the left segment of the string.

L = T

The effort (E) applied balances the tension (T) in the right segment of the string.

E = T

MA = `"Load (L)"/"Effort (E)"`

= `T/T`

= 1

Calculation of Velocity Ratio (VR):

Let the distance moved by the effort downwards be d_E. Since the string is inextensible, the load moves upwards by the exact same distance d_L.

d_E = d_L

VR = `("Distance moved by Effort" (d_E))/("Distance moved by Load" (d_L))`

= `(d_E)/(d_E)`

= 1