Physics - Combining Vectors
OCR A-Level Physics 2022
Combining Vectors
Combining Vectors is Physics - Resolving VectorsA in reverse, or vice-versa.
Adding vectors tip to tail
What is the golden rule for adding vectors?
Always add vectors tip to tail.
Combine these vectors, a boat moving $10kmh^{-1}$ across a $10kmh^{-1}$ flowing river 
?
?
* $\sqrt{10^2 + 10^2} = \sqrt{200} = 10\sqrt{2} kmh^{-1}$
Using Pythagoras and trigonometry on vectors
When can Pythagoras be used to combine two vectors?
When two known forces are at a right angle.
How can you work out the angle between two forces?
Using trigonometry.
Slope and summit example
Visualise a diagram for a train travelling along a $2^{\circ}$ towards a $200m$ summit?
How could you find the length of the slope in this diagram ?
?- $\sin 2 \circ = \frac{200}{x}$
- $x = \frac{200}{\sin 2 \circ}$