## Essential University Physics: Volume 1 (3rd Edition)

a) $90\ J$ b) $360 \ J$
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: $W =\int_0^3cxydx + \int_0^6 d dy$ $W =\int_0^36cxdx + 90=360 \ J$