Difference between physical property and physical quantity?

[christian0710]

Difference between physical property and physical quantity??

Hi I'm confused after reading the definitions of physical Quantity and physical property:

Definition from wikipedia: physical quantity= is a physical property of a phenomenon, body or substance that can be quantified by measurement.

So A coin has physical properties like mass, density, which can be quantified by measurement.
Does this mean that physical quantities and physical properties are the same thing,

Is Lenght, time and mass quantities, or are they properties of objects? And if i were to list them would I list them under quantity or property? Wikepedeas definitions have confused me.

 

[UltrafastPED]

Physical properties are intrinsic to the substance: density, magnetic permeability, conductivity, etc.

Physical quantities are a measure of how much: the weight of the sample, or its volume.

You can measure any physical property - thus you can measure the density by taking a prepared sample and measuring its volume and weight. If you have many different substances you can take measurements and calculate their densities.

If the samples are prepared in a standard way you will find that the density is a physical property of the material: each will have the same density within a margin of measurement error.

The act of measurement does not make that particular measurement a "physical property"; it means that you have a method of measurement - and hence a physical quantity. So you could measure a gram or a kilogram of lead, or 127.5 grams of lead ... these are just quantities of lead. But if you also measure their volumes (e.g., via water displacement) you can divide the weight by the volume for each sample and you should obtain the same value: this is the density, and it is a physical property of lead - it has a consistent value, and hence is a property.So what do you think of mass, length, and time now? Or temperature?

 

[Redbelly98]

From the OPs definition, any physical quantity is also a physical property. But I am trying to think if there are physical properties that are not quantifiable. The best I could come up with is the physical state (i.e. solid, liquid, gas, plasma). If you can't quantify it, then it's not a physical quantity.

 

[dauto]

Example
* Thermal expansion is a physical property
* The thermal expansion coefficient is a physical quantity.

 

[PJC01]

Hi there,

Thank you for bringing up this question. It is understandable that the definitions of physical quantity and physical property may be confusing, as they are closely related but not exactly the same.

A physical quantity is a measurable aspect of a physical phenomenon, body, or substance. In other words, it is a numerical value that expresses a physical property. For example, mass is a physical property that can be measured and expressed as a physical quantity in units such as kilograms or pounds.

On the other hand, a physical property is a characteristic or attribute of a physical system that can be observed or measured. It is a quality or trait that describes the behavior or state of a substance or object. Going back to the example of a coin, its physical properties include mass, density, color, and shape.

To summarize, physical quantities are the numerical values that represent physical properties. Physical properties, on the other hand, are the characteristics or traits that can be measured or observed.

To answer your question about length, time, and mass, they are all physical quantities because they are measurable aspects of physical systems. However, they can also be considered physical properties because they are characteristics of objects or substances.

I hope this helps to clarify the difference between physical quantity and physical property. Keep in mind that these terms are often used interchangeably, but it is important to understand their distinct definitions.