Mass is the **amount of matter** that a body contains and weight is the **action exerted by the force of gravity** on the body.

The mass of an object will always be the same, no matter where it is located. Instead, the weight of the object will vary according to the force of gravity acting on it.

For example: a person with a mass of 50 kg on Earth will have the same mass on the Moon. On the other hand, the weight of that same person will be 6 times less on the satellite than on the planet due to differences in the force of gravity. The force of gravity on the Moon is 1,622 m / s ^{2} and on Earth it is 9.8 m / s ^{2} .

Mass (m) | Weight (p) |
---|---|

It is a scalar quantity. | It is a vector magnitude. |

It’s the amount of matter a body has. | It is the action exerted by the force of gravity. |

Its value is constant. | Its value varies by position. |

It is measured with the balance. | It is measured with the dynamometer. |

Unit of measure: kilogram (Kg) and gram (g). | Unit of measure: Newton (N). |

Intrinsic quantity. | Extrinsic quantity. |

Index

## What is dough?

Mass is the amount of matter that an object has. It is a quantitative measure of a body’s resistance to acceleration. We can see it as the resistance of a crockery on the table when the tablecloth is pulled out.

Regardless of where the body is, the mass will always be the same, that is, it is an intrinsic quantity of matter.

Mass is an **extensive property of matter** , it depends on the quantity and size of the system under study. This means that if an object of mass equal to 1 kg, we remove 0.1 kg, and the mass will not be the same in the original object.

### How is mass measured?

Mass is normally measured by means of a balance, making a comparison with a known standard. In the International System of Units (SI), mass is expressed in kilogram (kg). Since May 20, 2019, the kilogram is defined in terms of Planck’s constant *h* , a fundamental constant of quantum physics that is universal:

This new measurement of the kilogram replaces the old definition of the kilogram, based on the **prototype of the international kilogram** , a cylinder of platinum and iridium that is kept in custody at the International Bureau of Weights and Measures in Sèvres, France in 1889.

## What is the weight?

Weight is the gravitational force exerted by the Earth or any other celestial body on an object, which is equal to the product of the object’s mass and the value of the local gravitational acceleration:

The value of the acceleration constant on Earth is 9.8 m / s ^{2} . By the formula it can be interpreted that the weight is proportional to the mass of the object.

Weight is a vector quantity since it has intensity, direction and sense. As such, weight is a measure resulting from the action that Earth’s gravity exerts on a body, and thus, weight is a variable value.

### How is weight measured?

The instrument used to determine weight is the dynamometer or spring scale. This consists of a protected coil spring that measures the force applied to the end of a pointer.

In the International System of Units (SI), the unit of weight is expressed in Newton (N), which is equal to:

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