Physics is the branch of science which deals with how and why things behave as they do.

A theory is a suggested explanation of how something works. It tries to explain all the facts known at the time

A scientist collects or uses information gathered by other scientists and through their powers of observations to discover new fact

Measuring devices called instruments help us make more accurate observations

Examples of instruments are meter sticks, rulers, measuring tape, vernier calipers and many more

However all these instruments have different purposes. For exaple to measure a straight line we use a ruler, to meaure a small curve we use opsiometers, to meaure a large curve we use a trundle wheel and to measure the diameter of a circular object we use vernier callipers.

Scientists must be able to present their results or findings in a clear way

If reading is taken from an angle and is misread this is called the "Error of Parallax"