What is the difference between mass and weight?

By Michael Bootle
Updated 2024-04-07 09:53:22 | Published 2018-12-20 04:53:26
  • Blog
    • Add to favorites
    • Join our community in exploring insightful stories, tips, and experiences that inspire and inform. The iMedix Blog is your go-to destination for connecting with others and enriching your health knowledge.

    • Questions:
      372
What is the difference between mass and weight?

In everyday conversation, we often use the terms mass and weight interchangeably, asking, “How much do you weigh?” when we're actually referring to the quantitative properties of our bodies. However, to avoid confusion, it's essential to understand why mass cannot be equated to weight.

The figures displayed on a scale, whether it's a bag of strawberries or a hypothetical whale, not only help determine the cost of the berries or the size of the whale but also reveal other characteristics.

In scientific terms, mass is a physical value used as a measurement unit for a body, energy, and inertial gravity. This entails certain characteristics in terms of classical mechanics:

  1. Mass (m) is invariant: it doesn't depend on the choice of the reference system. For instance, a passenger on a train or aircraft doesn't drastically gain or lose weight during the movement of their vehicle. This relativity of the reference system is also inherent in determining speed.
  2. Mass is independent of the speed of body movement. However, inertia, the property that requires time to change speed, is determined by mass. For example, an elephant cannot accelerate immediately, while a mouse, being less inert, can change its speed faster.
  3. When two bodies interact, their masses are inversely proportional to the ratio of accelerations, a property of inertia. This discovery has helped determine the masses of planets, satellites, and other astronomical bodies, as alternative methods are nearly impossible.

It's crucial not to confuse mass and weight, the latter being the force with which a body is attracted by the Earth.

In nature, there are no “worlds without gravity,” only worlds of “small and large gravity,” where heavenly bodies are attracted with varying force. An individual's mass remains stable on different planets, but their weight varies depending on the gravitational force. For example, an astronaut weighing 80 kg on Earth would weigh almost zero in orbit, less than 15 kg on the Moon, and nearly 200 kg on Jupiter. However, their mass remains unchanged in all cases.

In conclusion, while mass and weight are related concepts, they are distinct and should not be used interchangeably. Understanding their differences can help us appreciate the complexities of physics and the universe we inhabit. As always, consult with a science educator or professional for a deeper understanding of these concepts.

User-thumb
Michael Bootle is verified user for iMedix

  • General Health
    • Add to favorites
    • The level of the general health is determined depending by the presence and severity of the vital body functions decompensation. In accordance with this, the doctor takes a decision on urgency and necessity of therapeutic measures.

    • Questions:
  • Obesity
    • Add to favorites
    • Obesity and overweight are the result of the abnormal or excessive fat deposits generation which can be harmful to the health. It is usually caused by excessive food intake and/or reduced energy consumption.

    • Questions:
  • Weight Loss
    • Add to favorites
    • A person start losing weight when such organs as the brain, the heart, the muscles does not receive enough nutrients for normal work, and they send a signal to the adipose tissue that it is time to use additional resources. In response to this signal, the fat cells begin lipolysis – the breakdown of fat – and supply the body with the necessary energy.

    • Questions: