Answer:
See below for answers and explanations
Step-by-step explanation:
<u>Problem 1</u>
Recall that the projection of a vector onto is .
Identify the vectors:
Compute the dot product:
Find the square of the magnitude of vector v:
Find the projection of vector u onto v:
Thus, B is the correct answer
<u>Problem 2</u>
Treat the football and wind as vectors:
Football:
Wind:
Add the vectors:
Find the magnitude of the resultant vector:
Find the direction of the resultant vector:
Because our resultant vector is in Quadrant II, the true direction angle is 6° clockwise from the negative axis. This means that our true direction angle is
Thus, C is the correct answer
<u>Problem 3</u>
We identify the initial point to be and the terminal point to be . The vector in component form can be found by subtracting the initial point from the terminal point:
Next, we find the magnitude of the vector:
And finally, we find the direction of the vector:
Keep in mind that since our vector is in Quadrant III, our direction angle also needs to be in Quadrant III, so the true direction angle is .
Thus, A is the correct answer
<u>Problem 4</u>
Add the vectors:
Determine the magnitude of the vector:
Find the direction of the vector:
Because our vector is in Quadrant II, then the direction angle we found is a reference angle, telling us the true direction angle is 17° clockwise from the negative x-axis, so the true direction angle is
Thus, A is the correct answer
<u>Problem 5</u>
A vector in trigonometric form is represented as where is the magnitude of vector and is the direction of vector .
Magnitude:
Direction:
As our vector is in Quadrant III, our true direction angle will be 75.75° counterclockwise from the negative x-axis, so our true direction angle will be .
This means that our vector in trigonometric form is
Thus, C is the correct answer
<u>Problem 6</u>
Write the vectors in trigonometric form:
Add the vectors:
Find the magnitude of the resultant vector:
Find the direction of the resultant vector:
Because our resultant vector is in Quadrant II, then our true direction angle will be 86° clockwise from the negative x-axis. So, our true direction angle is .
Thus, B is the correct answer