What is the displacement PQ?

Question 63

EasyOriginal question

A constant force $\vec{F} = 2\hat{i} + 2\hat{j} + \hat{k}$ moves a particle from $P(1, -1, 2)$ to $Q(3, 2, 1)$ . The work done is $\vec{F} \cdot \overrightarrow{PQ}$ .

What is the displacement $\overrightarrow{PQ}$ ?

-2\hat{i} - 3\hat{j} + \hat{k}

Correct answerYour answer

4\hat{i} + \hat{j} + 3\hat{k}

Correct answerYour answer

2\hat{i} + \hat{j} - \hat{k}

Correct answerYour answer

2\hat{i} + 3\hat{j} - \hat{k}

Correct answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer D

Correct answer: D

$\overrightarrow{PQ} = \vec{q} - \vec{p}$ .
$(3 - 1)\hat{i} + (2 + 1)\hat{j} + (1 - 2)\hat{k} = 2\hat{i} + 3\hat{j} - \hat{k}$ .

Worth noting

$2\hat{i} + \hat{j} - \hat{k}$ takes $2 - (-1)$ as 1.

Concept: The vector joining two points
Typical timeTypical: 90 s
Your timeYours: —

The rule this testsThe scalar product

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Ten questions from Vectors, at your own pace.

What is the displacement PQ?

Question 63

Explanation