1. Equations, Symbols and Graphs Unit 1 – Introduction to Physics

2. Vocabulary Symbolsequationgraph word equationsvariablesx-axis y-axisdependent variabletangent Independent variablegradient y-interceptx-interceptdelta ( Δ) origintablescalepoints Symbol equations

3. Equations, Symbols and Graphs All physical quantities and their units can be represented by symbols. These quantities are dependent in some way on other quantities. There is a relationship between them which can be expressed as an equation and shown on a graph. y = x 2

4. Equations, Symbols and Graphs An equation represents the relationship between two or more physical quantities. This relationship can be expressed as a word equation or as an equation relating symbols which represent the quantities. Symbol equations are used when a number of quantities are involved, making it easier to manipulate. Insert word equation and symbol equation example

5. Equations, Symbols and Graphs Symbols are used to represent physical quantities. The value of a physical quantity consists of a numerical value and its unit. Any symbol represents both a number and a unit. Example: m = 2.1 kg or a = 10 m/s 2

6. Equations, Symbols and Graphs Graphs A graph is a visual representation of the relationship between two quantities. It shows how one quantity depends on another. Points on a graph are plotted using the values for the quantities obtained during an experiment or by using the equation for the relationship if it is known.

7. Equations, Symbols and Graphs The two quantities plotted are called the variables. Graphing Rules ◦ Title all graphs. ◦ The (x) axis is always the independent variable. ◦ The (y) axis is always the dependent variable. ◦ Label all axes and their units ◦ Line graphs are best for science related data.

8. Equations, Symbols and Graphs ◦ Never connect the dots on your line graph, instead show the line or curve resulting from the points on your graph. ◦ Always make your graph readable. Never cram information in tight spaces. Never make them too small to read. Always use a ruler and always write neatly. If in doubt, use your computer!

9. Equations, Symbols and Graphs Insert Graphs diagram