the velocity ratio of a machine is 4
To calculate the velocity ratio of a machine, you need to know the distance or angular displacement covered by the input and output parts of the machine.
The velocity ratio (VR) of a machine is defined as the ratio of the distance or angular displacement moved by the input part to the distance or angular displacement moved by the output part.
Mathematically, VR = Distance covered by Input / Distance covered by Output
or VR = Angular displacement covered by Input / Angular displacement covered by Output.
In your case, if the velocity ratio (VR) of the machine is given as 4, it means that for every unit of distance or angular displacement covered by the input part, the output part covers 4 units of distance or angular displacement.
Note: The velocity ratio is a dimensionless quantity and does not have any units.
To calculate the actual values of the distances or angular displacements covered by the input and output parts, more information about the specific machine is required.