Which combination of an object's speed and journey time gives a distance travelled of 1 km1\text{ km}1 km?
Speed: 10 μm s−110\text{ }\mu\text{m s}^{-1}10 μm s−1, Journey time: 100 Ms100\text{ Ms}100 Ms
Speed: 100 m s−1100\text{ m s}^{-1}100 m s−1, Journey time: 0.1 ms0.1\text{ ms}0.1 ms
Speed: 1 nm s−11\text{ nm s}^{-1}1 nm s−1, Journey time: 1 Gs1\text{ Gs}1 Gs
Speed: 0.1 Gm s−10.1\text{ Gm s}^{-1}0.1 Gm s−1, Journey time: 100 μs100\text{ }\mu\text{s}100 μs
