Please help me with this question and EXPLAIN:
A plane leaves an airport flying north at 800 km/h. At the same time another planeleaves the same airport and flies south at 750 km/h. In how many hours will they be 4650 kilometres apart?
2007-06-19 12:29:06 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
as they are going in opposite direction,their relative speed with respect to each other would be 800+750=1550 kmph
Theefore time taken to be 4650 km apart
=4650/1550
=3 hours
2007-06-19 12:34:37 · answer #1 · answered by alpha 7 · 1⤊ 0⤋
Simple! Let h = the number of hours until they are 4650km apart. Both planes are going to fly this amount of time, but in opposite directions,which means add their speeds to find out how fast they are moving away from each other. And distance equals speed times time, right? So
4650 = h(800 + 750)
(distance) = (time)*(speed)
4650 = h(1550)
4650/1550 = h = 3 hours
I bet the answer would have been easy for you if it had instead asked "A plane leaves an airport flying north at 1550 km/h. In how many hours will it be 4650 kilometres from the airport?" Think about it.
2007-06-19 19:39:42 · answer #2 · answered by Gary H 6 · 0⤊ 0⤋
3
2007-06-19 19:45:31 · answer #3 · answered by futureastronaut1 3 · 0⤊ 0⤋
The total distance between the two planes after each hour is 800+750 km which is 1,550 km
so just divide 4,650 by 1,550 to get the number of hours:
4650/1550 = 3
so it takes 3 hours
2007-06-19 19:34:43 · answer #4 · answered by grompfet 5 · 0⤊ 0⤋
800t +750 t = 4650
1550 t = 4650
t = 3 hours
2007-06-19 19:39:03 · answer #5 · answered by ironduke8159 7 · 0⤊ 0⤋
Thought you were going to ask, "Where did they bury the survivors?"! Actually, to determine distance, I would need to know whether the speed given is ground speed or air speed. I would also need to know the fuel range of each aircraft.
Aircraft speeds were usually expressed as air speed, but in the day of GPS, ground speed (the actual distance traveled over ground in a given time, expressed as distance per period of time. eg: km per hr.) is easy to determine.
Assuming that the speed given is ground speed, the answer would seem to be 3 hours, unless the aircraft do not have sufficient fuel range. If either or both need a fuel stop, the problem is obviously more complex.
2007-06-19 20:11:14 · answer #6 · answered by FlytesSchoolKid 1 · 0⤊ 0⤋
t=time
800t + 750t=4650
1550t=4650
4650/1550=3
It will take the planes 3 hours to be 4650 kilometers from one another.
2007-06-19 19:40:12 · answer #7 · answered by Cool Nerd At Your Service 4 · 0⤊ 0⤋
1550*t = 4650
t=3 hours
2007-06-19 19:35:04 · answer #8 · answered by Anonymous · 0⤊ 0⤋
This just a guess but 3 hours sounds likely...
2007-06-19 19:37:01 · answer #9 · answered by M_S 2 · 0⤊ 0⤋