1. Scalars and Vectors Flashcards
What is a scalar quantity?
A physical quantity that has magnitude but no direction
What is a vector quantity?
A physical quantity that has both magnitude and direction
Name 6 examples of scalar quantities
- Length/distance
- Speed
- Mass
- Temperature
- Time
- Energy
Name 5 examples of vector quantities
- Displacement
- Velocity
- Force (including weight)
- Acceleration
- Momentum
What happens when you add two or more vectors together?
You find the resultant
How do you find the resultant vector using scale diagrams?
Draw the vectors from tip to tail and then measure the length and angle of the resultant vector
How do you find the resultant vector using trigonometry?
If two vectors are perpendicular to each other:
- Use Pythagoras’ theorem to work out the length of the resultant force
- Use SOH CAH TOA to find the angle
What does it mean to resolve a vector?
It is the opposite of finding the resultant - split the vector into two components at right angles to each other
What are the components of a resolved vector?
- Horizontal
2. Vertical
How do you resolve a vector into its components?
- horizontal component = resultant force x cos θ
2. vertical component = resultant force x sin θ
How do you resolve a vector on a slope?
Choose directions parallel and perpendicular to the slope
Why is resolving a force useful?
The two perpendicular components of a vector do not affect each other meaning you can deal with the two directions separately
