Vectors and Components
Why Scalars Are Not Enough
What is a vector?
A vector is a quantity with magnitude and direction. Displacement, velocity, acceleration, and force are vectors.
Components
A vector can be split into parts along chosen axes. If a force makes an angle with the horizontal, then and .
Why components help
Breaking one angled vector into horizontal and vertical parts turns a 2D problem into two simpler 1D problems.
Scalar vs. vector
Scalar
- Magnitude only
- Examples: mass, time, speed
Vector
- Magnitude and direction
- Examples: displacement, velocity, force
Adding vectors
Vectors add according to direction, not just size. In components, you add parts together and parts together separately.
Which of the following is a vector?
Force has both magnitude and direction.
Correct answer: Force
If a vector has magnitude and angle from the horizontal, what is its horizontal component?
The horizontal component is .
Correct answer: F cos θ
Component method
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1
Step 1: Draw the vector on coordinate axes.
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2
Step 2: Identify the angle relative to the axes.
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3
Step 3: Use sine and cosine to find components.
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Step 4: Add components separately when combining vectors.