Physics - motion question?
Towards the end of a half-marathon, Sabina is 100 m from the finish line and is running at a constant speed of 5 m/s. Daniel, who is 140 m from the finish line, and is running at 4 m/s, decides to accelerate to try to beat Sabina. If he accelerates uniformly at 0.25 m/s^2 does he succeed?
- az_lenderLv 71 month agoFavourite answer
Sabina's time to finish the race is (100 m)/(5 m/s) = 20 seconds.
In 20 seconds, Daniel will speed up by 5 m/s,
that is, from 4 m/s to 9 m/s,
so his average speed during the 20 seconds will be 6.5 m/s,
and he'll cover a distance of 130 m.
He will not succeed in catching Sabina, as he'll still be 10m short of the finish line.