10K under 50 minutes... Please help (Read 324 times)

pedaling fool


     

    At the risk of sounding like an idiot...I'm going to say, No. Not without the wind giving it lift.

     

    Just to be clear...I'm assuming that the calibration is such that the plane makes no forward movement, thus no air flow over the wings. However, if a strong enough wind blows, then all bets are off


    Prince of Fatness

      Back to Physics 101 for you too, pedaling fool and Nemo. Sigh.

       

      I really hesitate to raise this here, but here is an actual head-scratcher about treadmills.

       

      A plane is standing on a large treadmill. The plane moves in one direction, while the treadmill belt moves in the opposite direction. This treadmill has a control system that tracks the plane speed and tunes the speed of the belt to be exactly the same (but in the opposite direction). Can the plane take off?

       

      I'm no physics guy but I think that this depends on wind velocity hitting the wings.  If I recall the wings are shaped such as the wind goes faster over the top of the wing than over the bottom.   This creates lift.  So the answer is it depends on the wind velocity.  I think.

       

      Anyway I hope that this helps the OP get their 10K under 50 minutes.

      Not at it at all. 

      LedLincoln


      not bad for mile 25

        Back to Physics 101 for you too, pedaling fool and Nemo. Sigh.

         

        I really hesitate to raise this here, but here is an actual head-scratcher about treadmills.

         

        A plane is standing on a large treadmill. The plane moves in one direction, while the treadmill belt moves in the opposite direction. This treadmill has a control system that tracks the plane speed and tunes the speed of the belt to be exactly the same (but in the opposite direction). Can the plane take off?

         

        Yes, if you put npaden's two fans in front of the plane.  They have to be really potent fans, though.  Don't bother starting the plane's engines.

        DavePNW


           

          Yes, if you put npaden's two fans in front of the plane.  They have to be really potent fans, though.  Don't bother starting the plane's engines.

           

          Maybe if you used one of Charlie Crist's podium fans.

          Dave

          Joann Y


             

            Anyway I hope that this helps the OP get their 10K under 50 minutes.

             

            I have a feeling that bhearn started this thread knowing that by page 9 we would be precisely where we are now. It's like the Kevin Bacon thing. How many pages until you get to the plane on a treadmill question?


            No Talent Drips

              Look, If that fecking plane can take off from a giant treadmill with no forward movement relative to the air mass around it (and the mill), then I have no fecking idea about pysics or aerodyamics or treadmills or Euclid or referece frames or Rubik's Cubes. Such a thing would cast serious doubts on my assertion that we have not taught a Wal-Mart to fly.

               Dei Gratia

               

              mikeymike


                 Don't bother starting the plane's engines.

                 

                As long as you tie a string to the nose of the plane to hold in place you shouldn't need the planes engines. It can just fly in the wind tunnel created by the giant, 300mph fans, over the airport-sized treadmill, like a giant wind sock.

                Runners run

                npaden


                  I think a Piper Super Cub could take off on a treadmill.  Especially one of those ones that SJ used to talk about for horses.

                   

                  https://www.youtube.com/watch?v=bPSElw8qEsI

                  Age: 50 Weight: 224 Height: 6'3" (Goal weight 195)

                  Current PR's:  Mara 3:14:36* (2017); HM 1:36:13 (2017); 10K 43:59 (2014); 5K 21:12 (2016)

                  LedLincoln


                  not bad for mile 25

                    As long as you tie a string to the nose of the plane to hold in place you shouldn't need the planes engines. It can just fly in the wind tunnel created by the giant, 300mph fans, over the airport-sized treadmill, like a giant wind sock.

                     

                    For that matter, don't bother starting the treadmill.  And, don't call it "flying," it's just a workout for the plane.

                    TeaOlive


                    old woman w/hobby

                      I had just about gotten rid of my head ache before opening this thread.

                       

                      Thanks.

                      steph  

                       

                       


                      Feeling the growl again

                        Hasn't Mythbusters actually done this one?

                         

                        MTA:  LINK, not that Mythbusters are the bastion of scientific method.

                        "If you want to be a bad a$s, then do what a bad a$s does.  There's your pep talk for today.  Go Run." -- Slo_Hand

                         

                        I am spaniel - Crusher of Treadmills

                         

                        npaden


                          Hasn't Mythbusters actually done this one?

                           

                          MTA:  LINK, not that Mythbusters are the bastion of scientific method.

                           

                          But the wheels on the plane were going twice as fast as normal when the plane took off!

                          Age: 50 Weight: 224 Height: 6'3" (Goal weight 195)

                          Current PR's:  Mara 3:14:36* (2017); HM 1:36:13 (2017); 10K 43:59 (2014); 5K 21:12 (2016)


                          Why is it sideways?

                            I've always wondered about this little mind bender.

                             

                            You are driving a car at 70mph on the interstate and you want to drive it up into the back of a trailer, itself being towed at, say, 69mph. When the car is driven into the trailer, does the driver have to radically let up on the gas in order to keep from zipping through the trailer at 70mph? Seems like the wheels of the car would have to slow down dramatically as they moved from the pavement to the trailer.

                             

                            Any advice on this would be helpful.


                            Feeling the growl again

                              Is that sort of like standing there flapping your arms?  Big grin

                               

                              Their test was not up to the theoretical model, because they could not speed up the "treadmill" fast enough to account for the low coefficient of friction of the wheels.  To match bhearns scenario, they would have just made the treadmill run to turn the wheels 100X as fast if that's what it took to keep the plane stationary.

                               

                              The clause about the treadmill sensing and keeping the plane stationary relative to the ground is what defines the outcome.

                               

                               

                              But the wheels on the plane were going twice as fast as normal when the plane took off!

                              "If you want to be a bad a$s, then do what a bad a$s does.  There's your pep talk for today.  Go Run." -- Slo_Hand

                               

                              I am spaniel - Crusher of Treadmills

                               


                              Feeling the growl again

                                Knight Rider - done that too.

                                "If you want to be a bad a$s, then do what a bad a$s does.  There's your pep talk for today.  Go Run." -- Slo_Hand

                                 

                                I am spaniel - Crusher of Treadmills