The work done by the force $\vec F=2\hat i-\hat j-\hat k$ in moving an object along the vector $3\hat i+2\hat j-5\hat k$ is:

–9 units 15 units 9 units None of these

9 units

Work $(2\hat i-\hat j-\hat k).(3\hat i+2\hat j-5\hat k)$ = 9 units