Ah Yeah 348 Posted April 18, 2015 Share Posted April 18, 2015 So for this maths question, I'm not sure if I got the correct answer (I got 'west' for the wind direction). If someone can double check my answer, it would be much appreciated! 35,000 won prize for the first person who can genuinely help me out! If there's other people who help me, I wouldn't mind giving out more 35Ks, since I don't use my wons. and send you a virtual gold star as well Already done! Jim is training for a mountain run. This run involves running east on a flat track for 2km to the mountain's base, then straight up the mountain’s steep side a further 3km to the top. This is halfway point of the course, where you turn around and run back the way you came. Jim can run at 12km/h on the flat. Uphill, he thinks he can run for 9km/h and he is capable of 15km/h on the downhill part of the course. The day before the race, Jim hears that windy conditions are expected. He knows that from experience that this will impact his speed out on the course. When the wind blows into his face, it will slow him down by 1km/h, but when it is at his back, he will speed up by the same amount. This applies to his speeds on the flat and on the slope. The wind will either blow directly from the east or directly from the west. b) From which direction should he hope the wind blows if he wishes to minimise his time? Link to comment Share on other sites More sharing options...
TellMeWhy 1,273 Posted April 18, 2015 Share Posted April 18, 2015 Blow west is faster. The flat is irrelevant. If the wind is blowing east, the slope takes 22.5 mins. If it is west, then less than 20 mins. Link to comment Share on other sites More sharing options...
Ah Yeah 348 Posted April 18, 2015 Author Share Posted April 18, 2015 Why? I hate these distance, speed and time problems omg. Link to comment Share on other sites More sharing options...
NATURAL NI KOISHITE 2,184 Posted April 18, 2015 Share Posted April 18, 2015 Devil Link to comment Share on other sites More sharing options...
Ah Yeah 348 Posted April 18, 2015 Author Share Posted April 18, 2015 Blow west is faster. Wait, really? Did you calculate it? I don't trust my maths. Link to comment Share on other sites More sharing options...
TellMeWhy 1,273 Posted April 18, 2015 Share Posted April 18, 2015 Wait, really? Did you calculate it? I don't trust my maths. The flat is irrelevant. If the wind is blowing east, the slope takes 22.5 mins. If it is west, then less than 20 mins. Oops sorry, I thought it was 2km up the slop. I will recalculate. Link to comment Share on other sites More sharing options...
Ah Yeah 348 Posted April 18, 2015 Author Share Posted April 18, 2015 The flat is irrelevant. If the wind is blowing east, the slope takes 22.5 mins. If it is west, then less than 20 mins. Oops sorry, I thought it was 2km up the slop. I will recalculate. Oh, I sent you the money already oops. Please recalculate. Thanks~ Link to comment Share on other sites More sharing options...
TellMeWhy 1,273 Posted April 18, 2015 Share Posted April 18, 2015 Oh, I sent you the money already oops. Please recalculate. Thanks~ West is 3/8 + 3/16 hrs, East is 3/10 + 3/14 hrs, whichever one is smaller. I don't have a calculator. East. If the wind blows towards west, the slope will take 33.75mins. If east, it takes about 30.83mins. Link to comment Share on other sites More sharing options...
Ah Yeah 348 Posted April 18, 2015 Author Share Posted April 18, 2015 West is 3/8 + 3/16 hrs, East is 3/10 + 3/14 hrs, whichever one is smaller. I don't have a calculator. Thank you Did you get your wons? Link to comment Share on other sites More sharing options...
TellMeWhy 1,273 Posted April 18, 2015 Share Posted April 18, 2015 Thank you Did you get your wons? Yeah. Thanks! Link to comment Share on other sites More sharing options...
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