2006-09-13 03:53:28 · 9 answers · asked by konwar d 1 in Science & Mathematics ➔ Mathematics
2.4 hours into the burning.
To solve, let the initial length of each candle be 1 unit.
The length of the candle after 't' hours is 1-t/3 for the three hour candle and 1-t/4 for the four hour candle. When the three hour candle is half as long as the four hour candle 2-2*t/3=1-t/4. Now just solve this equation for t.
2006-09-13 04:08:43 · answer #1 · answered by bruinfan 7 · 0⤊ 0⤋
If both candles start burning at the same time, after a time of 12 divided by 5 hrs, i.e. after 2 hrs and 24 minutes the length of the slower burning candle will be 2 upon 5 or 2/5 of its original length while that of the slower burning candle will be 1/5 of the original length; thus satisfying the condition that the length left of the slower burning candle should be twice of the length left of the faster burning one.
2006-09-13 11:22:57 · answer #2 · answered by innocent 3 · 0⤊ 0⤋
Candles do not burn uniformly. Even if you had a perfectly cylindrical candle, because of the way the wick soaks up melted wax, and because of pools forming in the top of the candle, two identical candles will not burn at a consistant rate.
I'm afraid this question is impossible to answer - the only way to do it would be by experiment, and even then you will not get the same answer twice!
2006-09-13 11:12:53 · answer #3 · answered by robcraine 4 · 0⤊ 1⤋
Let at t=0 both starts burning
let length of both the candles is Lm
rate at which 1st is burning is L/3m/hr
rate at which 2nd is burning is L/4m/hr
at time t L2=2L1
and L-L2/t=L/4....(1)as rate will always be same
and L-L1/t=L/3 ....(2)
divide 1 & 2
L-L2/L-L1=3/4
4L-4L2=3L-3L1
4L-8L1=3L-3L1
5L1=L
so L1=L/5
andL2=2L/5
so L-(L/5)/t=L/3
(4L/5)*3/L=t
t=12/5hr
2006-09-13 12:14:39 · answer #4 · answered by mahaveersoganiappu 2 · 0⤊ 0⤋
rate of burning of ist = L/3
" " " " 2nd= L/4
let after time t amt left in 2nd = 2(amt left in 1st)
L-(1/4)t = 2[L- (1/3)t]
solving we get t= 1.4hrs ans
2006-09-13 16:09:42 · answer #5 · answered by hanspie 2 · 0⤊ 0⤋
Okay, maybe you use equation 2(3-t) = 4-t?
So, 6-2t = 4-t.
So, t=2 hours?
2006-09-13 11:30:34 · answer #6 · answered by yljacktt 5 · 0⤊ 0⤋
innocent and James k are both correct.
2006-09-13 16:30:33 · answer #7 · answered by Anonymous · 0⤊ 0⤋
stop getting us to do your homework
2006-09-13 10:56:18 · answer #8 · answered by Anonymous · 0⤊ 0⤋
one and half hour
2006-09-13 11:16:10 · answer #9 · answered by ganesh n 1 · 0⤊ 0⤋