Two trains are moving toward each other on the same track, each traveling at 25 mph. When they are 100 miles apart a fly starts at the front of the first train and flies toward the second at 37 mph. When it reaches the second train it instantly reverses direction and flies back toward the first, again at 37 mph. It continues in this manner, flying back and forth between the trains at 37 mph until the trains collide and the fly is squished. How far does the fly fly?
2006-06-14 20:29:06 · 5 answers · asked by Scott R 6 in Science & Mathematics ➔ Mathematics
The two trains are moving towards each other at a speed of 25 mph each. Thus at a speed of 50 mph relative to each other. Since they started 100 miles apart, it will take them 2 hrs to reach each other.
They fly flew at a constant speed of 37 mph for 2 hrs. Thus the fly flew 74 miles.
2006-06-14 20:38:17 · answer #1 · answered by Eulercrosser 4 · 3⤊ 0⤋
the time taken by the trains to collide is 100/(25+25) which is 2 hours. as the trains are moving towards each other the effective speed i speed of train1 + speed of train2
the distance travlled by fly before the trains collide is the distance travelled by it in this 2 hours which is 37*2 = 74 miles
2006-06-15 03:41:13 · answer #2 · answered by writekdp 1 · 0⤊ 0⤋
use the concept of relative speed.
The R.S of fly wrt train= 62
The R.S of two trains= 50
FIRST round
So when distace =100
time taken by fly to reach other train= 100/62 hr due to R.Speed.
distance travelled by fly= 100/62* 37 = 59.68 miles..
distance at this time between trains= 100- 100/62* 50 = 19.35 mile (time * Rel.speed)
SECOND round
now distance = 19.35 mile
follow the same procedure, now from the other train side.
time taken by fly to reach other train= 19.35/62 hr
distance travelled by fly= 19.35/62* 37 = 11.55 miles..
distance at this time between trains= 19.35- 19.35/62* 50 = 3.745 mile (time * Rel.speed)
THIRD round
now distance = 19.35 mile
follow the same procedure, now from the other train side.
time taken by fly to reach other train= 19.35/62 hr
distance travelled by fly= 19.35/62* 37 = 11.55 miles..
distance at this time between trains= 19.35- 19.35/62* 50 = 3.745 mile (time * Rel.speed)
FOURTH round
now distance = 3.75 mile
follow the same procedure, now from the other train side.
time taken by fly to reach other train= 3.75/62 hr
distance travelled by fly= 3.755/62* 37 =2.24
distance at this time between trains= 3.75- 3.75/62* 50 = 0.73 mile (time * Rel.speed)
Similarly Last round distance travelled= 0.44 miles
adding all that total distance travelled= 59.68+11.55+2.24+0.44= 74 miles approx..
2006-06-15 03:56:43 · answer #3 · answered by Vivek 4 · 0⤊ 0⤋
dead, because fly can not go that fast fast he was on the windshield, and he was stuck on it
2006-06-15 03:38:41 · answer #4 · answered by tony b 1 · 0⤊ 0⤋
ahh my head hurts
2006-06-15 03:54:06 · answer #5 · answered by Anonymous · 0⤊ 0⤋