Questions: Vector A has magnitude a = 800 m and direction θ = 30.0°, whereas B has magnitude B = 400 m and θ = 210.0°. What is R = A + B?
R = [ ]ˆi + [ ]ˆj m
Transcript text: Vector A has magnitude a = 800 m and direction θ = 30.0°, whereas B has magnitude B = 400 m and θ = 210.0°. What is R = A + B?
R = [ ]ˆi + [ ]ˆj m
Solution
Solution Steps
Step 1: Convert Vector A to Component Form
First, we need to convert vector \( \mathbf{A} \) from its magnitude and direction to its component form. The components of vector \( \mathbf{A} \) can be found using the following formulas:
\[
A_x = a \cos \theta
\]
\[
A_y = a \sin \theta
\]
Given \( a = 800 \) m and \( \theta = 30.0^\circ \):
\[
A_x = 800 \cos 30.0^\circ = 800 \times 0.8660 = 692.8 \, \text{m}
\]
\[
A_y = 800 \sin 30.0^\circ = 800 \times 0.5000 = 400.0 \, \text{m}
\]
Step 2: Convert Vector B to Component Form
Next, we convert vector \( \mathbf{B} \) to its component form using the same approach:
\[
B_x = B \cos \theta
\]
\[
B_y = B \sin \theta
\]
Given \( B = 400 \) m and \( \theta = 210.0^\circ \):
\[
B_x = 400 \cos 210.0^\circ = 400 \times (-0.8660) = -346.4 \, \text{m}
\]
\[
B_y = 400 \sin 210.0^\circ = 400 \times (-0.5000) = -200.0 \, \text{m}
\]
Step 3: Add the Components of Vectors A and B
Now, we add the corresponding components of vectors \( \mathbf{A} \) and \( \mathbf{B} \) to find the resultant vector \( \mathbf{R} \):
\[
R_x = A_x + B_x = 692.8 + (-346.4) = 346.4 \, \text{m}
\]
\[
R_y = A_y + B_y = 400.0 + (-200.0) = 200.0 \, \text{m}
\]
Final Answer
The resultant vector \( \mathbf{R} \) in component form is:
\[
\boxed{R = 346.4 \, \hat{i} + 200.0 \, \hat{j} \, \text{m}}
\]