Correct Answer - Option 4 : 9 units
Concept:
We know that, work done, \(\left( W \right) = \vec F \cdot \vec d\) ---(1)
Calculation:
Given, \(d= 3\hat i + 2 \hat j-5 \hat k{\:}and {\:} \vec F = 2\hat i - \hat j - \hat k\)
Using equation (1)
\(w=\left( 2\hat i - \hat j - \hat k\right)\cdot\left(3\hat i+1\hat j-5 \hat k\right)\)
= 6 – 2 + 5
= 11 – 2 = 9 units