$\"\"$

\

Thre particle moving from $\"\"$ to $\"\"$ .

\

The constant unit force vector makes with the positive $\"\"$ -axis.

\

The work done is $\"\"$ .

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$\"\"$ .

\

Substitute $\"\"$ , $\"\"$ and $\"\"$ .

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$\"\"$

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$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$ .

\

$\"\"$

\

$\"\"$ .