A man is driving along in his trusty Ford truck with his (modified, since they normally don't activate below 35mph) cruise control set at 30 mph. He comes upon a hill. The hill is exactly one mile up one side, and one mile down the other for a total of two miles. He continues at his current 30 mph up the hill.

How fast would he have to drive down the other side (neglect any necessary acceleration or deceleration) to average 60 mph for the entire two miles he is on the hill?

I'll post the answer/explanation in a day or so. Until then, wrong answers will get buzzed. If you've heard this problem before, please refrain from posting the explanation, but you can post the answer, and mention that you've heard the problem previously.

Hint: remember that rate times time equals distance.

Jason

 

Dude:

If you drive 60 mph then 1 mile =1 minute.
Therefore 30 mph 1 mile = 2 minute up the hill.
If you want to average the 2 miles at 60 mph then it should take 2 minutes.
if your first leg is at 30 mph and takes 2 minutes then it is impossible at any speed on the down hill leg to AVERAGE 60 mph.

Maybe cool if you could go like mach 1 for 1 mile.

Anyways, no matter what the answer, i would always beat driving a Dodge or Chebby......


Call me an idiot if my thinking is incorrect.

Vegas

 

Party pooper. But, you're essentially correct. Theoretically, the speed of light would be the right answer, as time slows down at that speed, but as much as we like our Ford trucks, none of them go THAT fast.

Jason

 

Vegas is correct...trick question...try another question

Chris

 

Well,due to the fact that his cruise control refused to react in a timely matter,the truck slowed to approx 25mph while going up the incline.This caused KT,um I mean the driver to get impatient and put the pedal to the metal.Where as upon reaching the crest of the hill he was doing about 120mph,which launched him like the dukes of hazzard.Good thing too,because on the other side of the hill was an old dodge truck,in its normal condition,broke down in the middle of the road.Upon seeing this,KT,um I mean the driver.by impulse,immediately hit the brakes,which by the way become defective after launch.So,figuring into the equation the loss of speed caused by leaving two skid marks across the roof of that old dodge,and the reduction of speed caused by wind resistance from KT,um I mean the driver sticking his arm out the window to wave at the moron dumb enough to buy a dodge in the first place,I would have to say he was doing 90mph on touchdown.Whereby he slammed on the brakes to pick up that fine lookin babe in the daisy duke shorts who was hitchhiking because she was dumb enough to go for a ride with some dummy in a dodge who was broke down aways back on the hill.Upon entering KT`s,um I mean the driver`s truck,she said,Nice Ford truck you have here,lets go back to your place,Causing KT,um I mean the driver to put the pedal to the metal again!So,in conclusion,I say 90mph,two,never buy a dodge,and three,if you see one broke down,look for a cute babe hitchhiking!And If my answer is wrong,I should at least get a reputation point or two,because it took so long for me to type this!

 

I dunno, KT. It was certainly a creative story, but Vegas-V10 already gave the correct explanation. To average 60mph over 2 miles, one would have to take 2 minutes to travel those 2 miles. Since the guy drove his Ford up the hill (one mile) at 30 mph, that already took the full 2 minutes, so he essentially has zero time to get down the other side in order to average 60 mph. Hence the speed of light (instantaneous) answer.

Now, I'm somewhat partial to Dodges, so if it had been a ShoveMeOrStay in your story, I would have given you a rep point. Aww, heck, I'm feeling generous....

Jason

 

Ok,let me ask you this,,,
If you saw a fine lookin babe at the bottom of the hill in a pair of daisy dukes,how long would it take you to get to the bottom of the hill?

 

I plead the Fifth--I'm married.

 

Ok,give us another one.Even if I get it wrong,i can still have fun makin up an answer! After all,I was the smartest kids in the 8th grade for 4 years straight!

 

Well my wife is 54 and still in pre-school!!!!!!

 

KT is right - the time would be up before the crest of the hill - you invariably lose one or two MPH in a climb.

Even if this were not so - at the crest, you would have to have a truck capable of instantaneous matter transport to get to the end of the course in time.