$\"\"$

An overhead garage door has two springs one on each side of the door.

Force required to stretch each spring $\"\"$ foot is $\"\"$ pounds.

Hooks law: $\"\"$ .

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

$\"\"$

The door moves total of $\"\"$ feet.

Spring stretch only one half the distance the door travels due to pulley.

Work done by the object in moving from $\"\"$ to $\"\"$ is $\"\"$ .

Here $\"\"$ and $\"\"$ .

$\"\"$

$\"\"$ in-lb.

Total work done by the pair of springs is $\"\"$ in-lb.

$\"\"$

Work done by the pair of springs is $\"\"$ in-lb.