posted by Donald .
In reahcing her destination, a backpacker walks with an average velocity of 1.29 m/s, due west. This average velocity results because she hikes for 6.44 km with an average velocity of 2.59 m/s, due west, turns around, and hikes with an average velocity of 0.44 m/s, due east. How far east did she walk?
net distance divided by total time is 1.29m/s
Since time = distance/speed,
(6400-d)/(6400/2.59 + d/.44) = 1.29
d = 817m or .817km
check: she walked west for 6440/2.59 = 2486 s
she walked east for 817/.44 = 1857s
net distance from start: 5623m
total time hiking: 2486+1857 = 4343s
5623m/4343s = 1.29m/s