# measurements

```Measurements
Length

Length is a measure of how long an object is.

The standard SI (international system of units) of length is
the meter (m)

We can measure the length using a meter tape.

1 km = 1000 m

1 m = 10 dm = 100 cm = 1000 mm
Mass

Mass is the amount of matter in an object &amp; it is typically fixed
(doesn’t change).

The SI unit of mass is the Kilogram (kg)

We can measure mass by using a balance.

1kg = 1000 g

1 ton = 1000 kg
Weight

Weight is a force that measures the pull of gravity on an object.

Weight is not constant, it changes with location.

Weight is measured in Newton (N)

Weight = mass X gravity

N.B gravity on earth is constant (9.8 m/𝒔𝟐 )
Time:

Time is a measure of how long it takes to do something

The SI unit of time is the seconds (s)

We can measure time by using a stopwatch.

1 minute = 60 sec

1 hour = 60 min = 3600 sec
Temperature

Temperature is a measure of how hot an object is.

The SI unit of temperature is Kelvin (K)

We can measure temperature using thermometer.

K= ˚C + 273
Volume

The volume of an object is the amount of space and object occupies.

It is measure in 𝒎𝟑

Volume of a regular shape:

Area of base X height

Volume of a rectangular block= Length X width X height

Volume of a liquid can be found by pouring it into a measuring
cylinder and read the volume from the scale.

Volume of an irregular shape:

An irregular solid doesn’t have sides that can be easily measured.

Water is poured into a measuring cylinder until it is half full.

Volume of water is measured.

The solid is added to the water gently.

Volume of water is read again.

The difference in water volume before and after adding the solid is
the solid’s volume
Density

Density is the mass of an object per unit volume.

It is measured in kg/𝑚3

Density = Mass / volume

1. Weigh the solid using balance.

2. Calculate its volume

3. Divide its mass by its volume
```