Download vector cheat sheet - Hatboro

Vector Cheat Sheet
Graphical Method:
Vectors in 2-D:
When utilizing the graphical method, follow these steps:
1. Define your scale
2. Draw your vectors using the tip-to-tail method.
3. Draw the resultant vector.
4. Measure the vector and the angle.
5. Describe the direction in terms of degrees and direction (N, N of E, W, W of S, etc)
Trigonometry Method:
When calculating the resultant vector of a right triangle…
1. Use the Pythagorean Theorem to find the magnitude of the vector. (vector’s sketched tip to tail)
2. Use a trigonometric function…sine, cosine, tangent…to find the angle.
3. Use N, S, E, W, N of E, etc. to describe the direction of the angle.
Parallelogram Method:
When solving for the resultant of two vectors…you can also use the parallelogram method. You can
use graphical or trig.
1. Draw the vectors starting from the origin.
2. Complete the parallelogram.
3. Draw the vector from the start corner to the end corner.
4. For graphical, measure the resultant vector with a ruler & give answer with respect to scale.
5. For trig, use Pythagorean theorem & sin, cos, tan.
Law of Cosines:
For vectors NOT at 90 degrees, use Law of Cosines: R2 = A2 + B2 -2ABcosѳ
Vector Components: (Trig)
When calculating the components of a vector from the resultant.
1. Find the x component of the vector using trig.
2. Find the y component of the vector using trig.
Multiple Vectors:
Finding Resultant for multiple vectors…
1. Find the x and y components for each of the vectors.
2. Add all the x components.
3. Add all the y components.
4. Make a right triangle from the sum of x and the sum of y.
5. Find the resultant using trig or graphical. (trig is easier)