Home
Class 11
PHYSICS
The resultant of vec(A) and vec(B) make...

The resultant of `vec(A)` and `vec(B)` makes an angle `alpha` with `vec(A)` and `omega` with `vec(B)` , then:-

A

`alpha lt beta`

B

`alpha lt beta` if `A lt B`

C

`alpha lt beta` if `A gt B`

D

`alpha lt beta`if `A=B`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the relationship between the angles and the magnitudes of the vectors involved. Let's break it down step by step. ### Step 1: Understand the Vectors and Angles We have two vectors, \(\vec{A}\) and \(\vec{B}\). The resultant vector \(\vec{R}\) of these two vectors makes an angle \(\alpha\) with \(\vec{A}\) and an angle \(\omega\) with \(\vec{B}\). ### Step 2: Use the Law of Sines According to the law of sines in a triangle formed by the vectors, we can relate the angles and the sides opposite to them. The law states that: \[ \frac{R}{\sin(\omega)} = \frac{B}{\sin(\alpha)} \] This means that the ratio of the length of the resultant vector \(\vec{R}\) to the sine of the angle \(\omega\) is equal to the ratio of the length of vector \(\vec{B}\) to the sine of the angle \(\alpha\). ### Step 3: Apply the Law of Cosines We can also use the law of cosines to relate the sides and angles in the triangle formed by \(\vec{A}\), \(\vec{B}\), and \(\vec{R}\): \[ R^2 = A^2 + B^2 + 2AB\cos(\beta) \] Where \(\beta\) is the angle between \(\vec{A}\) and \(\vec{B}\). ### Step 4: Analyze the Angles From the triangle formed by the vectors, we know that: \[ \alpha + \omega + \beta = 180^\circ \] This implies that if \(\alpha\) increases, \(\beta\) must decrease and vice versa. ### Step 5: Compare the Angles If we assume that \(\alpha < \beta\), then according to the triangle inequality, the side opposite to the larger angle (which is \(\beta\)) must be greater than the side opposite to the smaller angle (which is \(\alpha\)). Therefore, we can conclude that: \[ |\vec{B}| > |\vec{A}| \] ### Conclusion Thus, the correct relationship derived from the angles and the sides is that: \[ \alpha < \beta \implies |\vec{B}| > |\vec{A}| \] ### Final Answer The resultant vector \(\vec{R}\) makes an angle \(\alpha\) with \(\vec{A}\) and an angle \(\omega\) with \(\vec{B}\) such that \(\alpha < \beta\) and \(|\vec{B}| > |\vec{A}|\). ---

To solve the problem, we need to analyze the relationship between the angles and the magnitudes of the vectors involved. Let's break it down step by step. ### Step 1: Understand the Vectors and Angles We have two vectors, \(\vec{A}\) and \(\vec{B}\). The resultant vector \(\vec{R}\) of these two vectors makes an angle \(\alpha\) with \(\vec{A}\) and an angle \(\omega\) with \(\vec{B}\). ### Step 2: Use the Law of Sines According to the law of sines in a triangle formed by the vectors, we can relate the angles and the sides opposite to them. The law states that: ...
Promotional Banner

Topper's Solved these Questions

  • UNIT DIMENSION, VECTOR & BASIC MATHS

    BANSAL|Exercise EXERCISE - 2 [MULTIPLE CORRECT CHOICE TYPE]|6 Videos
  • UNIT DIMENSION, VECTOR & BASIC MATHS

    BANSAL|Exercise EXERCISE - 2 [MATRIX TYPE]|1 Videos
  • UNIT DIMENSION, VECTOR & BASIC MATHS

    BANSAL|Exercise EXERCISE- 3 (SECTION - B)|1 Videos
  • KINETIC THEORY OF GASES

    BANSAL|Exercise Section-B|13 Videos

Similar Questions

Explore conceptually related problems

The resultant of vec(a) and vec(b) makes alpha with vec(a) and beta with vec(b) , then (a,b represent magnitudes of respective vectors) :

Two vectors vec(A) and vec(B) inclined at an angle theta have a resultant vec(R ) which makes an angle alpha with vec(A) . If the directions of vec(A) and vec(B) are interchanged, the resultant will have the same

If vec a*vec b=0 and vec a+vec b makes an angle of 30^(@) with vec a, then

The resultant vec(C ) of vec(A) and vec(B) is perpendicular to vec(A) . Also, |vec(A)|=|vec(C )| . The angle between vec(A) and vec(B) is

The resultant of two velocity vectors vec(A) and vec(B) is perpendicular to vec(A) . Magnitude of Resultant vec(R ) is equal to half magnitude of vec(B) . If the angle between vec(A) and vec(B) is (30 theta)^(@) , then value of theta is ?

The resultant of two vectors vec(A) and vec(B) is perpendicular to the vector vec(A) and its magnitudes is equal to half of the magnitudes of vector vec(B) (figure). The angle between vec(A) and vec(B) is

The angle between two vectors vec(A) and vec(B) is theta . The resultant of these vectors vec(R ) makes an angle of theta//2 with A. which of the following is true?

Let vec a,vec b,vec c be three unit vectors such that |vec a+vec b+vec c|=1 and vec a is perpendicular to vec b. if vec c makes angle alpha and beta with vec a and vec b respectively,then cos alpha+cos beta=

Vectors vec(A) and vec(B) include an angle theta between them If (vec(A)+vec(B)) and (vec(A)=vec(B)) respectively subtend angles apha and beta with A, then (tan alpha+tan beta) is

BANSAL-UNIT DIMENSION, VECTOR & BASIC MATHS-EXERCISE - 1 [SINGLE CORRECT CHOICE TYPE]
  1. The two vectors A=2hat(i)+hat(j)+3hat(k) and B=7hat(i)-5hat(j)-3hat(k...

    Text Solution

    |

  2. 0.4hat(i)+0.8hat(j)+chat(k) represents a unit vector, when c is :-

    Text Solution

    |

  3. The resultant of vec(A) and vec(B) makes an angle alpha with vec(A) ...

    Text Solution

    |

  4. I started walking down a road to day-break facing the sun. After walki...

    Text Solution

    |

  5. If |vec(A)+vec(B)|=|vec(A)|=|vec(B)| then the angle between vec(A) and...

    Text Solution

    |

  6. which of the following is not true ? If vec(A)=3hat(i)+4hat(j) and vec...

    Text Solution

    |

  7. If vector vec(A)=hat(i)+2hat(j)+4hat(k) and vec(B)=5hat(i) represent t...

    Text Solution

    |

  8. If vec(a) be a unit vector, then :-

    Text Solution

    |

  9. If two numerical equal forces P and P acting at a point produce a resu...

    Text Solution

    |

  10. Given that vec(A)+vec(B)=vec(R) and vec(A)+2vec(B) is perpendicular...

    Text Solution

    |

  11. The value of lambda for two perpendicular vectors vec(A)=2vec(i)+lamb...

    Text Solution

    |

  12. The resultant of two vectors of magnitude 3 units 4 units is 1 unit. ...

    Text Solution

    |

  13. If vec(i) and vec(j) are unit vectors along x-axis and y-axis respecti...

    Text Solution

    |

  14. The angle subtended by vector vec(i)+vec(j) with x-axis is :-

    Text Solution

    |

  15. Moment about point whose coordinate is (1,2,3) of a force represented ...

    Text Solution

    |

  16. If vec(A) and vec(B) denote the sides of a parallelogram and its area ...

    Text Solution

    |

  17. A vector perpendicular to (hat(i)+hat(j)+hat(k)) and (hat(i)-hat(j)-...

    Text Solution

    |

  18. The unit vector along vec(i)+vec(j) is :-

    Text Solution

    |

  19. Two constant forces vec(F)(1) and vec(F)(2) acts on a body of mass 8 k...

    Text Solution

    |

  20. Figure shows three vectors a, b and c. If RQ=2PR, which of the followi...

    Text Solution

    |