1. PHY115 – Sault College – Bazlurslide 1 Proportionality

2. PHY115 – Sault College – Bazlurslide 2 Proportionality http://en.wikipedia.org/wiki/Proportionality_(mathematics ) In mathematics, two quantities are called proportional - if they vary in such a way that one of the quantities is a constant multiple of the other, or equivalently if they have a constant ratio.

3. PHY115 – Sault College – Bazlurslide 3 Proportionality The variable y is said to be proportional (or sometimes directly proportional) to the variable x, if there exists a constant non-zero number k such that The relation is often denoted: and the constant ratio is called the proportionality constant or constant of proportionality of the proportionality relation.

4. PHY115 – Sault College – Bazlurslide 4 Examples If you travel at a constant speed, then the distance traveled is proportional to the time spent traveling, with the speed being the constant of proportionality. The circumference of a circle is proportional to its diameter, with the constant of proportionality equal to . On a map drawn to scale, the distance between any two points on the map is proportional to the distance between the two locations the points represent, with the constant of proportionality being the scale of the map. The amount of force acting on a certain object from the gravity of the Earth at sea level is proportional to the object's mass, with the gravitational constant being the constant of proportionality.

5. PHY115 – Sault College – Bazlurslide 5 Proportionality Two Variables illustrating Direct Proportionality. XY 00 24 48 816 32 Graph of the Data

6. PHY115 – Sault College – Bazlurslide 6 Proportionality Directly ProportionalInversly Proportional y = 1/x. 3

7. PHY115 – Sault College – Bazlurslide 7 Proportionality Voltage & Current Graph: Resistive Load

8. PHY115 – Sault College – Bazlurslide 8 Non-Proportionality Current and Voltage relationship of a resistance wire and a filament bulb

9. PHY115 – Sault College – Bazlurslide 9 Non-Proportionality Current and Voltage relationship of a Diode