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About Vectors Introduction — Class 10 IB

Represent vectors, perform vector addition and scalar multiplication, and apply to geometry. This topic is part of the IB Class 10 mathematics syllabus (chapter: Unit 6). On this page you can practice 60 questions across three difficulty levels — 20 easy, 20 medium, and 20 hard — each with a visual step-by-step solution, plus a timed 35-question mastery test with a live leaderboard. Worked examples and sample questions from the topic are below.

Vectors Introduction — solved examples for Class 10 IB

Example 1easy

Which of the following statements correctly distinguishes between a scalar and a vector quantity?
  1. A)A scalar quantity has magnitude only, while a vector quantity has direction only.
  2. B)A scalar quantity has both magnitude and direction, while a vector quantity has magnitude only.
  3. C)A scalar quantity has magnitude only, while a vector quantity has both magnitude and direction.
  4. D)Both scalar and vector quantities have magnitude and direction.

Step-by-step solution

  1. A scalar quantity is defined by its magnitude alone (e.g., mass, time, temperature).
  2. A vector quantity is defined by both its magnitude and its direction (e.g., displacement, velocity, force).
  3. Therefore, the correct distinction is that scalars have only magnitude, while vectors have both magnitude and direction.

Answer: A scalar quantity has magnitude only, while a vector quantity has both magnitude and direction.

Example 2medium

Which of the following quantities is a vector quantity?
  1. A)Mass
  2. B)Temperature
  3. C)Displacement
  4. D)Time

Step-by-step solution

  1. A vector quantity is defined as a quantity that has both magnitude and direction.
  2. Mass, Temperature, and Time are scalar quantities as they only have magnitude.
  3. Displacement, however, has both magnitude (the distance moved) and direction (the direction of movement from the starting point to the end point).

Answer: Displacement

Example 3hard

If A, B, C are three distinct points with position vectors **a**, **b**, **c** respectively, and **c** = (1-k)**a** + k**b** for some scalar k, what can be concluded about points A, B, C?
  1. A)A. A, B, C are always collinear.
  2. B)B. A, B, C are collinear only if k = 0 or k = 1.
  3. C)C. A, B, C are always vertices of a triangle.
  4. D)D. A, B, C are collinear only if **a**, **b**, **c** are zero vectors.

Step-by-step solution

  1. The given equation is **c** = (1-k)**a** + k**b**.
  2. Rearrange the equation: **c** - **a** = k**b** - k**a** => **c** - **a** = k(**b** - **a**).
  3. This means the displacement vector from A to C (vector(AC)) is a scalar multiple of the displacement vector from A to B (vector(AB)). Since vector(AC) = k × vector(AB) and they share the common point A, the points A, B, C must be collinear.

Answer: A. A, B, C are always collinear.

Practice questions on Vectors Introduction

  1. Q1.easy

    Consider a triangle PQR where vectors are represented by the directed line segments. Which vector equation correctly represents the Triangle Law of Vector Addition for this triangle?
    1. A)\vec{PQ} + \vec{QR} = \vec{PR}
    2. B)\vec{PR} + \vec{RQ} = \vec{PQ}
    3. C)\vec{QP} + \vec{PR} = \vec{QR}
    4. D)\vec{PQ} + \vec{RP} = \vec{QR}
    Show answer

    Answer: \vec{PQ} + \vec{QR} = \vec{PR}

    Hint: The Triangle Law states that if two vectors are represented by two sides of a triangle taken in order, their sum is the third side taken in the opposite order.

  2. Q2.easy

    Two vectors, \vec{a} and \vec{b}, are considered equal. Which of the following *must* be true?
    1. A)They have the same starting point.
    2. B)They are parallel and have the same magnitude, but can point in opposite directions.
    3. C)They have the same magnitude and the same direction.
    4. D)They represent the same physical quantity and are collinear.
    Show answer

    Answer: They have the same magnitude and the same direction.

    Hint: Recall the strict definition of equal vectors. What properties must they share?

  3. Q3.easy

    If a non-zero vector \vec{v} is multiplied by a positive scalar 'k' (where k > 1), what happens to the vector k\vec{v}?
    1. A)Its magnitude decreases, and its direction reverses.
    2. B)Its magnitude increases, and its direction remains the same.
    3. C)Its magnitude remains the same, but its direction changes.
    4. D)Both its magnitude and direction change unpredictably.
    Show answer

    Answer: Its magnitude increases, and its direction remains the same.

    Hint: Consider how scalar multiplication affects both the length (magnitude) and orientation (direction) of a vector.

  4. Q4.medium

    Consider two points A(2, 5) and B(7, 1). Express the vector AB in component form.
    1. A)[5, -4]
    2. B)[-5, 4]
    3. C)[9, 6]
    4. D)[5, 4]
    Show answer

    Answer: [5, -4]

    Hint: To find the displacement vector AB, subtract the coordinates of the initial point A from the coordinates of the terminal point B.

  5. Q5.medium

    Given vectors p = [3, -2] and q = [-1, 4], find the resultant vector p + q.
    1. A)[2, 2]
    2. B)[4, -6]
    3. C)[-4, 6]
    4. D)[2, -2]
    Show answer

    Answer: [2, 2]

    Hint: To add vectors in component form, add their corresponding x-components and y-components separately.

  6. Q6.medium

    If vector v = [-4, 7], calculate the vector 3v.
    1. A)[-12, 21]
    2. B)[12, -21]
    3. C)[-1, 10]
    4. D)[-7, 10]
    Show answer

    Answer: [-12, 21]

    Hint: When multiplying a vector by a scalar, multiply each component of the vector by that scalar.

  7. Q7.hard

    In quadrilateral PQRS, M, N, O, P are the midpoints of sides PQ, QR, RS, SP respectively. Which of the following vector equations, using position vectors from an origin O, proves that MNOP is a parallelogram?
    1. A)A. vector(MN) = vector(PO)
    2. B)B. vector(MN) = vector(OP)
    3. C)C. vector(MO) = vector(NP)
    4. D)D. vector(MP) = vector(NO)
    Show answer

    Answer: A. vector(MN) = vector(PO)

    Hint: For a quadrilateral to be a parallelogram, opposite sides must be parallel and equal in length. This translates to their displacement vectors being equal.

  8. Q8.hard

    Given two non-zero, non-parallel vectors **p** and **q**. If (x+2y)**p** + (2x-y)**q** = 5**p** + 5**q**, find the value of x - y.
    1. A)A. 0
    2. B)B. 1
    3. C)C. 2
    4. D)D. 3
    Show answer

    Answer: D. 3

    Hint: If two vectors are non-zero and non-parallel, then a linear combination of them equaling another linear combination implies the coefficients of corresponding vectors must be equal.

  9. Q9.hard

    Given **u** = 3**i** + 4**j** and **v** = -**i** + 2**j**. Find the magnitude of the vector **w** = 2**u** - 3**v**.
    1. A)A. √221
    2. B)B. √205
    3. C)C. √185
    4. D)D. √193
    Show answer

    Answer: B. √205

    Hint: First, calculate the vector **w** by performing scalar multiplication and vector subtraction. Then, find the magnitude of the resulting vector.

These are 9 of the 60 questions available for Vectors Introduction. Start practicing above to unlock visual solutions, AI coaching, and the topic leaderboard — completely free.