Physics

Problem

Runner A starts from a track’s origin at

t=0

and runs in a straight line at

4.0\,\text{m\,s}^{-1}

. Runner B starts from the same origin

30\,\text{s}

later, running in the same direction. If runner B catches runner A exactly

200\,\text{s}

after B begins running, what is runner B’s constant speed? a)

4.5\,\text{m\,s}^{-1}

4.2\,\text{m\,s}^{-1}

4.6\,\text{m\,s}^{-1}

6.1\,\text{m\,s}^{-1}