### Mass:

Mass is the quantity of matter contained in a body. With System Internationale (S.I) unit, the standard unit of mass is kilogram and the measurement of the mass of a body is carried out with the aid of chemical balance or beam balance in the laboratory and these instruments can measure up to 0.001g, which is the reading accuracy of the beam or chemical balance.

The mass of an object is measured by comparing it to a known mass on the arm of the chemical or beam balance. Other instruments that can be used to determine the mass of an object include electronic balance, triple beam balance, lever balance, etc.

### Weight:

Weight (W) of an object is the gravitational pull of the earth on a body. It is measured with the aid of an instrument known as spring balance and the S.I unit of weight is Newton (N). The weight of a body varies from place to place on the earthâ€™s surface.

The difference between mass and weight is stated as follows:

Mass | Weight |
---|---|

It is measured in kilograms (kg) | It is measured in Newton (N) |

It is measured with chemical/beam balance | It is measured with a spring balance |

Mass is constant | Weight varies |

Mass is a scalar quantity | Weight is a derived quantity |

Mass is a fundamental quantity | Weight is a derived quantity |

### Relationship Between Mass And Weight:

The relationship between mass and weight is the formula that connects mass and weight. This formula is used in calculations, to either calculate the mass of a given weight of an object or to calculate the weights of a given mass of an object.

The formula is: Â Â Weight = Mass x Acceleration due to Gravity

Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Weight = m*g

Example:

i. Calculate the weight of a mass 350g. (g = 10ms^{-2} )

**Solution**:

**Values given:**

Mass = \( \scriptsize 350g \)

Convert this to kg which is the standard unit

Mass = \( \scriptsize 350g \\ = \frac{350}{1000} \\ = \scriptsize 0.350kg \)

**Formula:**

Weight = mass x acceleration due to gravity

W = m x g

**Solution:**

Weight = 0.350kg x 10ms^{-2}

Weight = 3.5N