$\"\"$

Work done is $\"\"$ , where F is the force and u is the position vector.

Force vector is $\"\"$ .

The position vector is $\"\"$ .

The work done is $\"\"$

Substitute $\"\"$ and $\"\"$ in $\"\"$ .

$\"\"$

The work done is $\"\"$ .

$\"\"$

The work done is $\"\"$ .