Question

Define Velocity ratio with reference to a machine?

Answer 1

Definition

Velocity ratio is the ratio of the velocity at which effort is applied on a machine to the velocity at which load moves.

Formula

If D is the displacement caused by an effort in time ‘t’, such that ‘d’ is the displacement caused by the load at the same time, then :

$$\begin{gathered} Velocityoftheeffort=\frac{D}{t} \\ Velocityoftheload=\frac{d}{t} \\ \therefore Velocityratio\left(VR\right)=\frac{Velocityofeffort}{Velocityofload} \\ VR=\frac{{\displaystyle \frac{D}{t}}}{{\displaystyle \frac{d}{t}}} \\ VR=\frac{D}{d} \end{gathered}$$

Thus, velocity ratio is also defined as the ratio of displacement of the effort to the displacement of load in the same interval of time.