Jack and Jill ran a 200 meter race. Jill ran the race in 25 seconds and won by 5 meters; that is Jack had run only 195 meters when Jill crossed the finish line. They decide to race again, but this time Jill starts 5 meters behind the starting line. Assuming that both runners run at the same pace as before, who will win the second race and by how many seconds? (Hint: It's not a tie)
2007-02-10 03:08:50 · 10 answers · asked by unpredictedmystery 3 in Science & Mathematics ➔ Mathematics
Jill will win by 0.015 seconds. Jill ran the first race with a speed of 8 meters per second and Jack ran it in 7.8 meters per second. The second race Jill will run 205 meter at 8 meters per second in 25.625 second and Jack will run 200 meters at 7.8 meters per second in 25.640 seconds. A difference of 15 1/1000ths of a second.
2007-02-10 03:15:51 · answer #1 · answered by Anonymous · 3⤊ 0⤋
Jill win the race by ---- 0.016025 sec
speed of jack is 195/25 m/s
speed of jill is 200/25 m/s
distance travelled by jack in 2nd race= 200m
distance travelled by jill in 2nd race= 205m
time taken by jack in 2nd race= 200/195 * 25
time taken by jill in 2nd race= 205/200*25
2007-02-10 04:01:21 · answer #2 · answered by Ashima 1 · 0⤊ 0⤋
Jill ran the 200 meter race in 200/25 m/s= 8m/s
In that time Jack was running 195/25= 7.8m/s
Jill in the re-ran race of 200+5= 205m, so she completed the race in 205/8 = 25.625s.
Jack has to run 200m with a speed of 7.8, so he completes it in 200/7.8= 25.641s.
There Jill wins by 25.641-25.625= 0.016s or 16milliseconds.
2007-02-10 03:21:31 · answer #3 · answered by The exclamation mark 6 · 0⤊ 0⤋
according to my calc jill will win the second race by .016025641 second.
solution-
jill case - 200 m race in = 25 sec.
so he will take = ( 25/200)(205) =25.625 sec.
jack case - 195 m race in = 25 sec.
so he will take = (25/195)(200) = 25.64102564 sec.
this shows that jack will take more time =
25.64102564 - 25.635 =0.16025641 sec.
so jill will win the race by 0.16025641 sec.
hey buddy i tried my level best to solve this question........hopefully this is write....
2007-02-10 03:33:44 · answer #4 · answered by punjabi j 2 · 0⤊ 0⤋
Jack runs at 195meters/25 seconds = 7.8 m/s
Jill runs at 200meters/25 seconds = 8 m/s
If Jill starts 5 meters behind the starting line, she'll have to run 205 meters, which will take her 205/8 = 25.625 seconds
Jack will run 200 meters to the finish, which will take him 200/7.8 = 25.641 seconds
Jill will finish first by 25.641 -25.625= .016 seconds
2007-02-10 03:23:26 · answer #5 · answered by Laura 2 · 0⤊ 0⤋
Jack is going to run 200 m. It takes him 25 seconds to run 195 m, so he will run 200 in 25 * 200/195 sec = 25.641 sec.
Jill is going to run 205 m. It takes her 25 seconds to run 200 m, so she will run 205 in 25 * 205/200 seconds = 25.625 sec.
Jill squeaks out a victory of less than .02 secs.
2007-02-10 03:19:32 · answer #6 · answered by Anonymous · 0⤊ 0⤋
jill's time: 25.625s
jack's time: 28.57s
clearly jill again wins the race by approx. 3 seconds
2007-02-10 03:22:01 · answer #7 · answered by Apoorv g 2 · 0⤊ 2⤋
Jill speed: 200m/25s=8m/s
Jack: 195m/25s=39/5(m/s)
Time for second race
Jill: 205m/8m/s=25.625s
Jack: 200m/(39/5)(m/s)=25.641s
Therefore Jill will win again.
2007-02-10 03:20:22 · answer #8 · answered by Javier 2 · 0⤊ 0⤋
jill won
2007-02-10 04:59:19 · answer #9 · answered by xandrasings 2 · 0⤊ 0⤋
Jill wins by 0.016 seconds
2007-02-10 03:19:35 · answer #10 · answered by Anonymous · 0⤊ 2⤋