a jetliner can fly 6.5 hours on a full load of fuel. Without any wind, it flies at a speed of 2.10 x 10^2 m/s. the plane is to make a round-trip by heading due west for a certain distance, turning around, and then heading due east for the return trip. during the whole flight, the plane encounter 55.0 m/s wind from the jet stream, which blows from west to east. what is the maximum distance that the plane can travel due west and just be able to return home?
A swimmer, capable of swimming at a speed of 1.3 m/s in still water (the swimmer can swim with a speed of 1.3 m/s relative to the water) starts to swim directly across a 2.2 km wide river. However the current is 0.91 m/s and it carries the swimmer downstream
a) how long does it take the swimmer to cross the river?
b) how far downstream will the swimmer be upon reaching the other
2007-09-24 09:12:57 · 1 answers · asked by Anonymous in Science & Mathematics ➔ Physics
For the jetliner, the total time in the air is 6.5 hrs, or 6.5*3600 seconds.
the distance in both directions must be the same, but the times will be different because of the different ground speeds.
When heading west, ground speed is
v=210-55
so the distance is
d=155*t1
when flying East, ground speed is
v=210+55,
so the distance is
d=265*t2
and t1+t2=6.5*3600,
solve for d
d=1870 km
2) as long as the swimmer maintains a heading directly perpendicular to shore then
a) t=2200/1.3 seconds
b) in that time the swimmer will be carried downstream
t*0.91 meters
j
2007-09-24 09:29:14 · answer #1 · answered by odu83 7 · 0⤊ 0⤋