in how much time will they be 18 km apart?
(please answer with statements and steps
2006-12-20 21:51:35 · 4 answers · asked by christine 1 in Science & Mathematics ➔ Mathematics
solve the sum using linear equations
2006-12-20 22:06:53 · update #1
Their relative speed with respect to each other is
5/2 + 2 km/hr = 9/2 km/hr
d = r*t, t = d/r
t = 18 km/(9/2)km/hr
t = 4 hr
2006-12-20 21:57:17 · answer #1 · answered by Helmut 7 · 0⤊ 0⤋
What do you mean by saying speeds are 5/2 and 2 km/hr. If you mean that one is going with a speed of 5/2 kmph and other with 2kmph then the answer follows
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The relative velovity gets added up as they are moving in opposite direction. Hence the relativ velocity is (5/2)+2=4.5kmph
Ie. To be 4.5 km apart they take 1hr. To be 18km apart they will take 18/4.5=4 hours
2006-12-21 05:57:36 · answer #2 · answered by Bunty Rocks 2 · 0⤊ 0⤋
18/(5/2+2)=4 hrs
but they may keep going till they meet at the other side of the Earth:) Depends on the perimeter of the latitude or longitude they are on.*grin*
2006-12-21 05:58:08 · answer #3 · answered by DedB 2 · 0⤊ 0⤋
distance apart in one hr.=5/2km+2km
...................................... = 9/2 km
to make distance 18 divide 18 by 9/2
=18*2/9
=4hr
it will take 4 hr
2006-12-21 07:02:29 · answer #4 · answered by girish sahare 2 · 0⤊ 0⤋