2. Learning Objectives : 1.To fully understand the terms resultant force and resolving into perpendicular components 2.To be able to visualise the geometry and trigonometry present within such problems 3.To be able to solve inclined plane problems Book Reference : Pages 90-96

3. Before we begin: The Wikispace has several links to alternative video explanations for adding vectors, resultant vectors and resolving vectors. Clear thinking.... Testing what you currently understand Clearing up the concepts in your mind... Handouts Eureka video.....

4. Definitions & Tools 1 Resultant vector : The single equivalent vector which can exactly replace a collection of vectors. This can be found either by scale drawing or in the case of vectors at right angles Pythagoras’ theorem and trigonometry

5. Definitions & Tools 2 Resolving Vectors Into Perpendicular Components When confronted with a collection of vectors it is convenient to resolve each vector into equivalent perpendicular components. Once all the components have been found the sum in each direction can be simply found. From this we can find the resultant

6. R Resultant force 31.5° Horizontal force of 3.8N Weight 6.2N R Resultant force Horizontal force of 3.8N Weight 6.2N 58.5° 31.5° 58.5° Note basic rules of geometry in terms of the other angles present

7. 7.3N Horizontal force of 3.8N Weight 6.2N 58.5° 31.5° 58.5° sin 31.5° = O/H = 3.8/7.3 = cos 58. 5° = A/H and sin 58.5° = O/H = 6.2/7.3 = cos 31. 5° = A/H Spend a few moments using a protractor to draw a right angled triangle. Measure the angles and press the buttons on your calculator until you’re happy that the above is true

8. 30°