if the cyclist had 2 haours head start, after how many hours does the car overtakes the cyclist?
2007-04-12 14:49:38 · 13 answers · asked by ohoma 1 in Science & Mathematics ➔ Mathematics
80x=20x+2(20)
60x=40
x=2/3
so he will catch the cylist after 2/3 an hour or 40 min.
2007-04-12 14:52:59 · answer #1 · answered by leo 6 · 1⤊ 0⤋
the answer is 30 mins
the cyclist is 40 miles away 20 mph x 2 hours = 40
the car is going 80 mph 1/2 of 80 = 40 since an hour is 60 mins long and half of 60 = 30 the car will overtake the bike in only 30 mins.
2007-04-12 15:00:30 · answer #2 · answered by maddog 5 · 0⤊ 0⤋
One assumption that is needed for this question:
That both the car and the cyclist is travelling on the same road, in the same direction, from the same starting point...
Let time be t, distance for both must be the same when car overtakes cyclist.
Then 20(2) + 20t = 80t
60t = 40
Hence time is 2/3 of an hour = 40 minutes
2007-04-12 15:10:29 · answer #3 · answered by looikk 4 · 0⤊ 0⤋
distance traveled by the cyclist is 20(t+2)
distance traveled by the car is 80(t)
they are equal when t=2/3, or 40 minutes after the car starts.
Easy check - in 2 hours, 40 minutes, the cyclist travels 8/3 times 20 miles, or 160/3 miles, and in 40 minutes the car travels 2/3 times 80 = 160/3 miles.
2007-04-12 14:56:40 · answer #4 · answered by David K 3 · 0⤊ 0⤋
80miles / 60min = 1.33miles a min. Well lets see he can travel approx. 1.33 miles a min 1.33miles X 30.5min = 40.57miles plus you have to add the time to the cyclist and if he does 20mph a half hour would take him 10miles so add the 10miles to the car. 1.33miles X 7.5min = 9.98miles so add the two together and you get 40.57miles + 9.98Miles = 50.55miles in which the car would overtake the cyclist and the time ends up being approx 38min to overtake the cyclist!
2007-04-12 14:55:15 · answer #5 · answered by Anonymous · 0⤊ 0⤋
The biker will travel a distance of 40 +20t
The car will travel 80t
So 80t = 40 +20t
60t = 40
t = 2/3 hour
2007-04-12 14:57:04 · answer #6 · answered by ironduke8159 7 · 0⤊ 0⤋
1 hr (30 mins actually)
2 hour head start= 40 miles
The car can do 80 miles in less than an hour
2007-04-12 14:53:35 · answer #7 · answered by Sparkle 3 · 0⤊ 1⤋
yes it is going to causee a strong impact. How strong would depend on where it hits the car. if it just hits the very front and clips of the headlight, no it is not going to caus injuries or anything. if it goes head on into the door yes it would probably cause injury's to people depending on where they were sitting and if you had seat belts on. did this happen to you or are you just considering getting drunk someday and going through a red light at 80 miles an hour?
2016-05-19 14:30:43 · answer #8 · answered by ? 3 · 0⤊ 0⤋
Half-an-hour.
2007-04-12 14:52:03 · answer #9 · answered by khrome_wind 5 · 0⤊ 1⤋
40 minutes, exactly
2007-04-12 14:51:49 · answer #10 · answered by thenextiommi 3 · 0⤊ 0⤋