Home
Class 11
PHYSICS
If the scalar and vector products of two...

If the scalar and vector products of two vectors `vecA and vecB` are equal in magnitude, then the angle between the two vectors is

A

`45^(@)`

B

`90^(@)`

C

`180^(@)`

D

`120^(@)`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the angle between two vectors \(\vec{A}\) and \(\vec{B}\) given that their scalar product and vector product are equal in magnitude. ### Step-by-Step Solution: 1. **Understand the Scalar Product**: The scalar (dot) product of two vectors \(\vec{A}\) and \(\vec{B}\) is given by: \[ \vec{A} \cdot \vec{B} = |\vec{A}| |\vec{B}| \cos \theta \] where \(\theta\) is the angle between the two vectors. 2. **Understand the Vector Product**: The vector (cross) product of two vectors \(\vec{A}\) and \(\vec{B}\) is given by: \[ \vec{A} \times \vec{B} = |\vec{A}| |\vec{B}| \sin \theta \] The magnitude of the vector product is given by \(|\vec{A} \times \vec{B}|\). 3. **Set the Scalar and Vector Products Equal**: According to the problem, the magnitudes of the scalar and vector products are equal: \[ |\vec{A} \cdot \vec{B}| = |\vec{A} \times \vec{B}| \] Substituting the expressions for the scalar and vector products, we have: \[ |\vec{A}| |\vec{B}| |\cos \theta| = |\vec{A}| |\vec{B}| |\sin \theta| \] 4. **Simplify the Equation**: Assuming \(|\vec{A}|\) and \(|\vec{B}|\) are not zero, we can divide both sides by \(|\vec{A}| |\vec{B}|\): \[ |\cos \theta| = |\sin \theta| \] 5. **Solve for \(\theta\)**: The equation \(|\cos \theta| = |\sin \theta|\) implies that: \[ \tan \theta = 1 \] The angles that satisfy this condition are: \[ \theta = 45^\circ \quad \text{or} \quad \theta = 225^\circ \] However, since we are looking for the angle between two vectors, we consider only the acute angle: \[ \theta = 45^\circ \] ### Final Answer: The angle between the two vectors \(\vec{A}\) and \(\vec{B}\) is \(45^\circ\).

To solve the problem, we need to find the angle between two vectors \(\vec{A}\) and \(\vec{B}\) given that their scalar product and vector product are equal in magnitude. ### Step-by-Step Solution: 1. **Understand the Scalar Product**: The scalar (dot) product of two vectors \(\vec{A}\) and \(\vec{B}\) is given by: \[ \vec{A} \cdot \vec{B} = |\vec{A}| |\vec{B}| \cos \theta ...
Promotional Banner

Topper's Solved these Questions

  • KINEMATICS

    CBSE COMPLEMENTARY MATERIAL|Exercise Numericals|26 Videos
  • GRAVITATION

    CBSE COMPLEMENTARY MATERIAL|Exercise MULTIPLE CHOICE QUESTIONS|19 Videos
  • KINETIC THEORY OF GASES

    CBSE COMPLEMENTARY MATERIAL|Exercise Objective question|20 Videos

Similar Questions

Explore conceptually related problems

The vector sum of two vectors vecA and vecB is maximum , then the angle theta between two vector is

The magnitude of scalar and vector products of two vectors are 48sqrt(3) and 144 respectively. What is the angle between the two vectors?

The magnitude of scalar and vector products of two vectors are 144 and 48sqrt(3) respectivley. What is the angle between the two vectors?

The magnitude of the vector product of two vectors vecA and vecB may not be:

The magnitude of the vectors product of two vectors |vecA| and |vecB| may be

The value of the sum of two vectors vecA and vecB with theta as the angle between them is

The magnitude of the vector product of two vectors is sqrt(3) times their scalar product. The angle between the two vectors is

If the magnitudes of two vectors are 3 and 4 and their scalar product is 6, then find the angle between the two vectors.

CBSE COMPLEMENTARY MATERIAL-KINEMATICS-M.C.Q.
  1. If the angle between the vectors vecA and vecB is theta, the value of ...

    Text Solution

    |

  2. For an object thrown at 45^(@) to the horizontal, the maximum height H...

    Text Solution

    |

  3. the circular motion of a particle with constant speed is

    Text Solution

    |

  4. At the uppermost point of a projectile, its velocity and acceleration ...

    Text Solution

    |

  5. If |vecA + vecB| = |vecA - vecB|, then the angle between vecA and vecB...

    Text Solution

    |

  6. The x and y coordinates of a particle at any time t is given by x = 7t...

    Text Solution

    |

  7. If K is the kinetic energy of a projectile fired at an angle 45°, then...

    Text Solution

    |

  8. A particle is moving eastwards with a velocity of 5 m//s. In 10 s the...

    Text Solution

    |

  9. A body dropped from top of tower falls through 60 m during the last 2 ...

    Text Solution

    |

  10. The angular velocity of second's hand of a watch will be.

    Text Solution

    |

  11. the angle between the vectors (hati+hatj) and (hatj+hatk) is

    Text Solution

    |

  12. If the scalar and vector products of two vectors vecA and vecB are equ...

    Text Solution

    |

  13. An object , moving with a speed of 6.25 m//s , is decelerated at a ra...

    Text Solution

    |

  14. The velocity time graph for the veticaly component of the velocity of ...

    Text Solution

    |

  15. In one second, a particle goes from point A to point B moving in a sem...

    Text Solution

    |

  16. A boat which has a speed of 5 km per hour in still water crosses a riv...

    Text Solution

    |

  17. A body projected at an angle with the horizontal has a range 300 m. th...

    Text Solution

    |

  18. What is the projection of vecA on vecB ?

    Text Solution

    |

  19. A person travels along a straight road for the first half length with ...

    Text Solution

    |

  20. A projectile rises to a height of 10 m and then falls at a distance of...

    Text Solution

    |