it is noon, and the spy is back friom space and driving a jeep through the sandy desert in the tiny principality of San Antonio. he is 32 km from the nearest point on a straight paved road. down the road 16km is a power plant in w/c band of international terrorists has placed a time bomb set to explode at 12:50 pm. the jeep can travel 48 km per hour in the sand and 80 km per hour on the paved road. if he arrives at the power plant in the shortest possible time, how long will our hero have to defuse the bomb?
2007-02-17 02:06:30 · 7 answers · asked by blaize 2 in Science & Mathematics ➔ Mathematics
also tell me what operation u used.. example, why phytagorean theorem?
2007-02-17 03:29:08 · update #1
First calculate the time required for him to cross the sand to the road:
Ts= distance/speed on sand
Ts= 32 km/ 48km/hr
Ts= 0.6666666666 hr * 60min/hr
Ts= 40 min
Now calculate the time required to traverse the road to the power station in the same manner:
Tr= distance/ speed on paved road
Tr= 16 km/ 80km/hr
Tr= 0.2 hr * 60min/hr
Tr= 12 min
Now calculate the total time to make it to the power plant:
t= Ts + Tr
t= 40 min + 12 min
t= 52 min
Since the bomb is rigged to go off at 12:50, and it's noon when he begins, that means he has 50min to drive to the plant and defuse the bomb. So to calculate the time he has remaining to defuse the bomb subtract the travel time (t) calculated above from the total time he has:
Tb= 50 min - t
Tb= 50min - 52min
Tb= -2 min
oops, times up...he was a little too slow!
2007-02-17 02:43:44 · answer #1 · answered by sciencewiz 4 · 0⤊ 1⤋
If he drive thru desert sands for 32 km first, he would reach the paved road in 40 mins (32/48 * 60) then another 12 mins (16/80 * 60) to reach the power plant on the paved road. Which means he will be too late. However, if he takes the shortest distance to the power plant, he needs to travel 35.78 km ( sqrt(16² + 32²)) thru the desert then he will only take 44.72 mins (35.78/48 * 60) to get there. This means he has 5.28 mins or 5 mins and 17 secs to defuse the bomb.
2007-02-17 10:49:28 · answer #2 · answered by euclidjr 2 · 2⤊ 0⤋
First calculate the time required to cross the sand to the road:
Ws= distance/speed on sand
Ws= 32 km/ 48km/hr
Ws= 0.6666666666 hr * 60min/hr
Ws= 40 min
Now calculate the time required to traverse the road to the power station in the same manner:
Wr= distance/ speed on paved road
Wr= 16 km/ 80km/hr
Wr= 0.2 hr * 60min/hr
Wr= 12 min
Now calculate the total time to make it to the power plant:
t= Ws + Wr
t= 40 min + 12 min
t= 52 min
Since the bomb is rigged to go off at 12:50, and it's noon when he begins, that means he has 50min to drive to the plant and defuse the bomb. So to calculate the time he has remaining to defuse the bomb subtract the travel time (t) calculated above from the total time he has:
Wb= 50 min - t
Wb= 50min - 52min
Wb= -2 min
too late.........
note: Wb,Ws,Wr are just variables i ve given names to.... nothin special...
2007-02-18 00:03:34 · answer #3 · answered by Anonymous · 0⤊ 1⤋
okay, that means he will have to travel 32km on sand first. The time he needs is 32/40=4/5 hours=48min. He then would have to travel 16km on road, 16/80=1/5hours=12minutes.
48min+12min=1hour. He will arrive there at 1.
I think it will be impossible for him to do it since the bomb would probably exploded by that time. I hope this helps. :)
2007-02-17 10:16:31 · answer #4 · answered by Juni Mccoy 3 · 0⤊ 1⤋
He will have about 5 minutes and 16 seconds if you calculate it with the pythagorean theorem
2007-02-17 10:51:54 · answer #5 · answered by Anonymous · 0⤊ 0⤋
If you go directly to the site thru the sand, you can get there in 44.7 minutes. Do the geometry. 35.77 miles to the site thru the sand. 48km/hour = 44.7 minutes.
2007-02-17 10:50:41 · answer #6 · answered by Anonymous · 0⤊ 0⤋
Fastest time is .73333hours = 44 minutes, so he has 6 minutes.
2007-02-17 12:20:29 · answer #7 · answered by ironduke8159 7 · 0⤊ 0⤋