What is the angle between \(\mathrm{Q}^{-}\) and the resultant of \(\mathrm{P}^{-}+\mathrm{Q}^{\rightarrow}\) and \(\mathrm{Q}^{\rightarrow}-\mathrm{P}^{\rightarrow}\) (A) \(90^{\circ}\) (B) \(60^{\circ} \quad\) (C) 0 (D) \(45^{\circ}\)

Short Answer

Expert verified
The angle between the vector \( \boldsymbol{Q^{-}} \) and the resultant of vectors \( \boldsymbol{P^{-} + Q^{\rightarrow}} \) and \( \boldsymbol{Q^{\rightarrow} - P^{\rightarrow}} \) can be calculated using the angle cosine formula. After finding the resultant vector and evaluating the necessary calculations, we find that the angle between the two vectors is \( \theta = 90^{\circ} \). So, the correct answer is (A) \( 90^{\circ} \).

Step by step solution

01

Find the Resultant Vector

First, let's find the resultant vector by adding \( \boldsymbol{P^{-} + Q^{\rightarrow}} \) and \( \boldsymbol{Q^{\rightarrow} - P^{\rightarrow}} \): \( \boldsymbol{R} = \boldsymbol{(P^{-} + Q^{\rightarrow}) + (Q^{\rightarrow} - P^{\rightarrow})} \) Step 2: Simplify the expression
02

Simplify the Resultant Vector

Now we simplify the expression by combining like terms: \( \boldsymbol{R} = \boldsymbol{ P^{-} + Q^{\rightarrow} + Q^{\rightarrow} - P^{\rightarrow} } \) \( \boldsymbol{R} = \boldsymbol{ Q^{\rightarrow} + Q^{\rightarrow} - P^{\rightarrow} + P^{-} } \) Step 3: Evaluate the condition given
03

Evaluate the Condition Given

Since the problem states \( \boldsymbol{Q^{-}} = -\boldsymbol{Q^{\rightarrow}} \) and \( \boldsymbol{P^{-}} = -\boldsymbol{P^{\rightarrow}} \), we can substitute and simplify: \( \boldsymbol{R} = \boldsymbol{ -Q^{-} - Q^{-} + P^{-} - P^{\rightarrow} } \) \( \boldsymbol{R} = \boldsymbol{ (P^{-} - Q^{-}) - (P^{\rightarrow} + Q^{-}) } \) Step 4: Find the angle between \( \boldsymbol{Q^{-}} \) and \( \boldsymbol{R} \)
04

Find the Angle Between Vectors

Now we need to find the angle \( \theta \) between \( \boldsymbol{Q^{-}} \) and \( \boldsymbol{R} \) using the formula: \( \cos{\theta} = \frac{\boldsymbol{Q^{-}} \cdot \boldsymbol{R}}{|\boldsymbol{Q^{-}}| |\boldsymbol{R}|} \) Step 5: Calculate the dot product
05

Calculate the Dot Product

By calculating the dot product between the two vectors, we get: \( \boldsymbol{Q^{-}} \cdot \boldsymbol{R} = (\boldsymbol{Q^{-}}) \cdot (\boldsymbol{(P^{-} - Q^{-}) - (P^{\rightarrow} + Q^{-})}) \) Step 6: Find the magnitudes of both vectors
06

Find the Magnitude of Vectors

Now we need to find the magnitudes of both \( \boldsymbol{Q^{-}} \) and \( \boldsymbol{R} \), using the formula: \( |\boldsymbol{Q^{-}}| = \sqrt{(\boldsymbol{Q^{-}})^2} \) \( |\boldsymbol{R}| = \sqrt{(\boldsymbol{(P^{-} - Q^{-}) - (P^{\rightarrow} + Q^{-})})^2} \) Step 7: Evaluate the angle cosine
07

Evaluate the Angle Cosine

By substituting the dot product and magnitudes into the angle cosine formula, we get: \( \cos{\theta} = \frac{\boldsymbol{Q^{-}} \cdot \boldsymbol{R}}{|\boldsymbol{Q^{-}}| |\boldsymbol{R}|} = 0 \) Since the cosine of the angle between two vectors is 0 when they are perpendicular, the angle between the two vectors is: \( \theta = 90^{\circ} \) So, the correct answer is (A) \( 90 ^{\circ} \).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

See all solutions

Recommended explanations on English Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free