Answer
(a) $14J$
(b) decrease
Work Step by Step
(a) We know that
$W=Fdcos\theta$
We plug in the known values to obtain:
$W=(50)(0.50)cos55^{\circ}$
$W=14J$
(b) If we increase the angle to $65^{\circ}$, then the work done by the janitor will decrease because in this case the smaller component of force will act along the direction of motion.
