MCQ
A force $\overrightarrow {F\,} = 6\hat i + 2\hat j - 3\hat k$ acts on a particle and produces a displacement of $\overrightarrow {s\,} = 2\hat i - 3\hat j + x\hat k.$ If the work done is zero, the value of $x$ is
- A$-2$
- B$0.5$
- C$6$
- ✓$2$
✓
Answer
Correct option: D.
$2$
d
(d)$W = \overrightarrow F .\overrightarrow s = (6\hat i + 2\hat j - 3\hat k).(2\hat i - 3\hat j + x\hat k) = 0$
(d)$W = \overrightarrow F .\overrightarrow s = (6\hat i + 2\hat j - 3\hat k).(2\hat i - 3\hat j + x\hat k) = 0$
$12 - 6 - 3x = 0$
==> $x = 2$
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