Answer
a) $ 90\ J$
b) $360 \ J$
Work Step by Step
a) We know that work is equal to the integral of force with respect to distance, and we know that any perpendicular component of a vector will not contribute to work. Thus:
$ W =\int_0^3cxydx + \int_0^6 d dy$
$ W =\int_0^3cx(0_dx + \int_0^6 d dy$
$W=6 \times 15 = 90\ J$
b) We use a similar process to find:
$ W =\int_0^3cxydx + \int_0^6 d dy$
$ W =\int_0^36cxdx + 90=360 \ J$
