1.3. Salad dressing* A simple salad dressing can be prepared by adding one part vinegar to three parts vegetable oil and beating the mixture vigorously using a whisk. The result is an emulsion in which vinegar droplets are dispersed in the oil. The palatability of the dressing depends on the volume V of an average vinegar droplet. If it is supposed that V depends on the whisking velocity (hand speed) U, the diameter D of the whisk wires, the oil viscosity, and the oil-water surface tension y, identify a set of dimensionless groups that might be used to quantify this process.