21. Scalars and Vectors are physical quantities and not objects. 22. For most quantities a unit is absolutely necessary to communicate values of that physical quantity . 23. Analogue devices, however, which express data using continuously variable physical quantities , were in wide use. 24. Without defining the physical quantities or their exact relationships, it is not physical or mathematical. 25. The sound field can be described using physical quantities like sound pressure and particle velocity. 26. Von Neumann and Morgenstern stated that the question of measurability of physical quantities was dynamic. 27. A digital signal is a physical quantity that alternates between a discrete set of waveforms. 28. For example, I have been working on physical quantity , physical constants and dimensionless quantities lately. 29. By 1871, he presented the " Remarks on the mathematical classification of physical quantities ". 30. For example, although torque and energy share the dimension, they are fundamentally different physical quantities .
