Mathematics · OCR H240 · Topic 1.10

Vectors

Vectors in two and three dimensions: magnitude, direction, position vectors and geometric problems.

  • 5 sub-topics
  • Taught in Year 13
  • 72 practice questions
  • 5 animated lessons

What the specification says

Every sub-topic OCR can examine in this topic, with its reference number from the official specification. The Y12 and Y13 tags show when each sub-topic is usually taught.

  1. 1.10a-bVectorsY13
  2. 1.10cMagnitude and direction of vectorsY13
  3. 1.10dBasic operations on vectorsY13
  4. 1.10e-fPosition vectors and distance between pointsY13
  5. 1.10g-hProblem solving using vectorsY13

Try 3 questions

Easy, medium and hard questions from this topic, each with a worked solutions and the mark for every step. All 72 questions in this topic, free, no account needed.

Vectors

Easy

Magnitude and unit vector · Year 12 · 2 marks

a\mathbf{a}=3i+4j{}= 3\mathbf{i} + 4\mathbf{j}
  1. Find ∣a∣|\mathbf{a}| and a unit vector in the direction of a\mathbf{a}.
    (2)
Show worked solutionHide worked solution
  1. Pythagoras.∣a∣|\mathbf{a}|=32+42{}= \sqrt{3^2 + 4^2}=5{}= 5
  2. Divide by the magnitude to get length 1.15(3i+4j)\tfrac{1}{5}(3\mathbf{i} + 4\mathbf{j})

Total2

  • MMethod mark: for a correct method, even with a slip.
  • AAccuracy mark: for a correct answer from a correct method.
  • BIndependent mark: for a correct fact or result on its own, with no method needed.
How did it go?

Report a problem with this question

Vectors

Medium

Parallel vectors · Year 12 · 2 marks

  1. Find kk such that 2i+kj2\mathbf{i} + k\mathbf{j} is parallel to 3i−6j3\mathbf{i} - 6\mathbf{j}.
    (2)

Check your answer before you look at the solution

Show worked solutionHide worked solution
  1. Parallel vectors are multiples of each other.3i−6j3\mathbf{i} - 6\mathbf{j}=3(i−2j){}= 3(\mathbf{i} - 2\mathbf{j}), so we need 2(i−2j)2(\mathbf{i} - 2\mathbf{j})
  2. k=−4k = -4

Total2

  • MMethod mark: for a correct method, even with a slip.
  • AAccuracy mark: for a correct answer from a correct method.
  • BIndependent mark: for a correct fact or result on its own, with no method needed.
How did it go?

Report a problem with this question

Vectors

Hard

Vectors in a parallelogram · Year 12 · 6 marks

OABCOABC is a parallelogram with OA→=a\overrightarrow{OA} = \mathbf{a} and OC→=c\overrightarrow{OC} = \mathbf{c}. MM is the midpoint of ABAB, and OMOM meets ACAC at XX.
  1. Find OX→\overrightarrow{OX} in terms of a\mathbf{a} and c\mathbf{c}.
    (6)
Show worked solutionHide worked solution
  1. AB→\overrightarrow{AB}=OC→{}= \overrightarrow{OC}=c{}= \mathbf{c}.OM→\overrightarrow{OM}=a{}= \mathbf{a}+12c{}+ \tfrac{1}{2}\mathbf{c}
  2. XX is on OMOM.OX→\overrightarrow{OX}=λ(a+12c){}= \lambda\left(\mathbf{a} + \tfrac{1}{2}\mathbf{c}\right)
  3. XX is also on ACAC.OX→\overrightarrow{OX}=a{}= \mathbf{a}+μ(c−a){}+ \mu(\mathbf{c} - \mathbf{a})
  4. Compare coefficients of a\mathbf{a} and c\mathbf{c}.λ=1−μ\lambda = 1 - \mu and 12λ=μ\tfrac{1}{2}\lambda = \mu
  5. λ=23\lambda = \tfrac{2}{3}, so OX→\overrightarrow{OX}=23a{}= \tfrac{2}{3}\mathbf{a}+13c{}+ \tfrac{1}{3}\mathbf{c}

Total6

  • MMethod mark: for a correct method, even with a slip.
  • AAccuracy mark: for a correct answer from a correct method.
  • BIndependent mark: for a correct fact or result on its own, with no method needed.
How did it go?

Report a problem with this question