A workboat passes a marker buoy while travelling along a straight channel at a constant speed of 2.0 m/s. A second workboat follows the same route and passes the buoy 30 s later, travelling in the same direction at a constant speed of 3.5 m/s.
How far does the first workboat travel after the second workboat passes the buoy and before it is overtaken?
80 m80\ \mathrm{m}80 m
60 m60\ \mathrm{m}60 m
140 m140\ \mathrm{m}140 m
45 m45\ \mathrm{m}45 m