Here's why:
* It's a ratio: Mechanical advantage is a ratio of output force to input force. It's a dimensionless quantity, meaning it has no units. It simply tells you how much the force is amplified by a machine.
* It depends on the system: Mechanical advantage is a property of a specific machine or system. It's not an intrinsic property of the object itself. The same object can have different mechanical advantages depending on how it's used.
* It's not conserved: Unlike physical quantities like energy or momentum, mechanical advantage doesn't need to be conserved. You can have machines with different mechanical advantages.
What is a physical quantity?
A physical quantity is a property of a physical system that can be measured and expressed numerically. It has a unit associated with it, for example, length (meters), mass (kilograms), time (seconds), etc.
While mechanical advantage isn't a physical quantity, it's still an important concept in physics and engineering because it helps us understand how machines amplify forces.
