Results 1 to 13 of 13

Thread: Brain Teaser

  1. #1
    Mostly Me Lucio's Avatar
    Join Date
    Mar 2007
    Location
    Tring
    Posts
    5,163
    Thanks
    443
    Thanked
    448 times in 351 posts
    • Lucio's system
      • Motherboard:
      • Gigabyte GA-970A-UD3P
      • CPU:
      • AMD FX-6350 with Cooler Master Seldon 240
      • Memory:
      • 2x4GB Corsair DDR3 Vengeance
      • Storage:
      • 128GB Toshiba, 2.5" SSD, 1TB WD Blue WD10EZEX, 500GB Seagate Baracuda 7200.11
      • Graphics card(s):
      • Sapphire R9 270X 4GB
      • PSU:
      • 600W Silverstone Strider SST-ST60F
      • Case:
      • Cooler Master HAF XB
      • Operating System:
      • Windows 8.1 64Bit
      • Monitor(s):
      • Samsung 2032BW, 1680 x 1050
      • Internet:
      • 16Mb Plusnet

    Brain Teaser

    Ok, a plane is sitting on a conveyor belt the size of that is set to run in the opposite direction to which the plane travels and can exert an infinite amount of force. The wheels have perfect grip and frictionless bearings so they can run at any speed. The plane throttles up to normal take off speed, what happens?

    (\___/) (\___/) (\___/) (\___/) (\___/) (\___/) (\___/)
    (='.'=) (='.'=) (='.'=) (='.'=) (='.'=) (='.'=) (='.'=)
    (")_(") (")_(") (")_(") (")_(") (")_(") (")_(") (")_(")


    This is bunny and friends. He is fed up waiting for everyone to help him out, and decided to help himself instead!

  2. #2
    I R Toff Pandi! TAKTAK's Avatar
    Join Date
    Mar 2008
    Location
    Vergon6
    Posts
    7,449
    Thanks
    549
    Thanked
    1,012 times in 747 posts
    • TAKTAK's system
      • Motherboard:
      • ASUS ROG STRIX B450-F GAMING
      • CPU:
      • Ryzen 7 3700X
      • Memory:
      • 16GB Corsair Vengeance LPX 3200MHz
      • Storage:
      • 500GB Samsung 970 EVO
      • Graphics card(s):
      • 5700 XT 50th Anniversary
      • PSU:
      • Be Quiet SFX-L 600W
      • Case:
      • Lian Li PC-O11 Mini
      • Operating System:
      • Windows 10
      • Monitor(s):
      • LG Ultrawide
      • Internet:
      • 200Mb FTTP

    Re: Brain Teaser

    Nothing
    Post Counts and Other Rewards, Rules, Folding@Home, Fans: Push vs Pull vs Push-Pull, Corsair PSU OEMs.

    Quote Originally Posted by razer121 View Post
    Would you like me to enter you? it would be my pleasure
    TAKTAK.co.uk

  3. #3
    Does he need a reason? Funkstar's Avatar
    Join Date
    Aug 2005
    Location
    Aberdeen
    Posts
    19,874
    Thanks
    630
    Thanked
    965 times in 816 posts
    • Funkstar's system
      • Motherboard:
      • Gigabyte EG45M-DS2H
      • CPU:
      • Intel Core2Quad Q9550 (2.83GHz)
      • Memory:
      • 8GB OCZ PC2-6400C5 800MHz Quad Channel
      • Storage:
      • 650GB Western Digital Caviar Blue
      • Graphics card(s):
      • 512MB ATI Radeon HD4550
      • PSU:
      • Antec 350W 80+ Efficient PSU
      • Case:
      • Antec NSK1480 Slim Mini Desktop Case
      • Operating System:
      • Vista Ultimate 64bit
      • Monitor(s):
      • Dell 2407 + 2408 monitors
      • Internet:
      • Zen 8mb

    Re: Brain Teaser

    Quote Originally Posted by Lucio View Post
    what happens?
    You get a thread of mamoth proportions.

    http://forums.hexus.net/general-disc...ight=treadmill

    ...and lots of arguing.

  4. #4
    Banhammer in peace PeterB kalniel's Avatar
    Join Date
    Aug 2005
    Posts
    30,748
    Thanks
    1,787
    Thanked
    3,285 times in 2,647 posts
    • kalniel's system
      • Motherboard:
      • Gigabyte Z390 Aorus Ultra
      • CPU:
      • Intel i9 9900k
      • Memory:
      • 32GB DDR4 3200 CL16
      • Storage:
      • 1TB Samsung 970Evo+ NVMe
      • Graphics card(s):
      • nVidia GTX 1060 6GB
      • PSU:
      • Seasonic 600W
      • Case:
      • Cooler Master HAF 912
      • Operating System:
      • Win 10 Pro x64
      • Monitor(s):
      • Dell S2721DGF
      • Internet:
      • rubbish

    Re: Brain Teaser

    You get stabbed in the eyes for bringing this up again

  5. #5
    0iD
    0iD is offline
    M*I*A 0iD's Avatar
    Join Date
    Jul 2003
    Location
    Happy Llama Land
    Posts
    13,247
    Thanks
    1,435
    Thanked
    1,209 times in 757 posts
    • 0iD's system
      • Motherboard:
      • Leave my mother out of it!
      • CPU:
      • If I knew what it meant?
      • Memory:
      • Wah?
      • Storage:
      • Cupboards and drawers
      • Graphics card(s):
      • Slate & chalk
      • PSU:
      • meh
      • Case:
      • Suit or Brief?
      • Operating System:
      • Brain
      • Monitor(s):
      • I was 1 at skool
      • Internet:
      • 28k Dialup

    Re: Brain Teaser

    http://forums.hexus.net/general-disc...treadmill.html

    Lift is created by air flowing over the wing. Airspeed = Lift No lift on a treadmill
    [
    Quote Originally Posted by Blitzen
    When I say go, both walk in the opposite direction for 10 paces, draw handbags, then bitch-slap each other!

  6. #6
    Welcome to stampytown! Salazaar's Avatar
    Join Date
    Dec 2004
    Location
    Oxford-ish
    Posts
    4,459
    Thanks
    505
    Thanked
    353 times in 254 posts
    • Salazaar's system
      • Motherboard:
      • Asrock B450m Steel Legend
      • CPU:
      • Ryzen 5 3600
      • Graphics card(s):
      • 5700 XT

    Re: Brain Teaser

    I saw the wheels off, patent the frictionless bearings and retire with more money than I can imagine.
    ____
    (='.'=)
    (")_(")

  7. Received thanks from:

    TheAnimus (25-06-2009)

  8. #7
    PHP Geek Flash477's Avatar
    Join Date
    Dec 2008
    Location
    Devon
    Posts
    822
    Thanks
    51
    Thanked
    72 times in 65 posts

    Re: Brain Teaser

    Quote Originally Posted by 0iD View Post
    http://forums.hexus.net/general-disc...treadmill.html

    Lift is created by air flowing over the wing. Airspeed = Lift No lift on a treadmill
    Not true, the thrust that pushes the plan forward is from the engines, not from the wheels, so the plane would still move forward as normal as the wheels just follow where the plane pushes them, not them pushing the plane. Thus the treadmill does not move.

  9. #8
    Seething Cauldron of Hatred TheAnimus's Avatar
    Join Date
    Aug 2005
    Posts
    17,164
    Thanks
    803
    Thanked
    2,152 times in 1,408 posts

    Re: Brain Teaser

    unless the treadmill is already rolling.
    throw new ArgumentException (String, String, Exception)

  10. #9
    Welcome to stampytown! Salazaar's Avatar
    Join Date
    Dec 2004
    Location
    Oxford-ish
    Posts
    4,459
    Thanks
    505
    Thanked
    353 times in 254 posts
    • Salazaar's system
      • Motherboard:
      • Asrock B450m Steel Legend
      • CPU:
      • Ryzen 5 3600
      • Graphics card(s):
      • 5700 XT

    Re: Brain Teaser

    Quote Originally Posted by TheAnimus View Post
    unless the treadmill is already rolling.
    Wouldn't make any difference, the wheels are perfect and frictionless (apparently) no energy would be transfered beyond them.
    ____
    (='.'=)
    (")_(")

  11. #10
    Mostly Me Lucio's Avatar
    Join Date
    Mar 2007
    Location
    Tring
    Posts
    5,163
    Thanks
    443
    Thanked
    448 times in 351 posts
    • Lucio's system
      • Motherboard:
      • Gigabyte GA-970A-UD3P
      • CPU:
      • AMD FX-6350 with Cooler Master Seldon 240
      • Memory:
      • 2x4GB Corsair DDR3 Vengeance
      • Storage:
      • 128GB Toshiba, 2.5" SSD, 1TB WD Blue WD10EZEX, 500GB Seagate Baracuda 7200.11
      • Graphics card(s):
      • Sapphire R9 270X 4GB
      • PSU:
      • 600W Silverstone Strider SST-ST60F
      • Case:
      • Cooler Master HAF XB
      • Operating System:
      • Windows 8.1 64Bit
      • Monitor(s):
      • Samsung 2032BW, 1680 x 1050
      • Internet:
      • 16Mb Plusnet

    Re: Brain Teaser

    Okies well to forstall a lot of arguing (hopefully), here's why the plane takes off normally.

    Both the planes thrust and the motion of the belt makes the wheels turn in the same direction (pushing from the centre or pulling from the bottom both result in the same circular motion.

    Therefore the wheels are turning at the speed of the conveyor PLUS the planes thrust, no matter how fast the belt turns, the wheel's movement is always belt speed (in opposite direction to the belt), plus the planes thrust.

    Therefore the conveyor belt has sod all effect on the plane other than to make the wheels spin really really fast.

    (\___/) (\___/) (\___/) (\___/) (\___/) (\___/) (\___/)
    (='.'=) (='.'=) (='.'=) (='.'=) (='.'=) (='.'=) (='.'=)
    (")_(") (")_(") (")_(") (")_(") (")_(") (")_(") (")_(")


    This is bunny and friends. He is fed up waiting for everyone to help him out, and decided to help himself instead!

  12. #11
    Welcome to stampytown! Salazaar's Avatar
    Join Date
    Dec 2004
    Location
    Oxford-ish
    Posts
    4,459
    Thanks
    505
    Thanked
    353 times in 254 posts
    • Salazaar's system
      • Motherboard:
      • Asrock B450m Steel Legend
      • CPU:
      • Ryzen 5 3600
      • Graphics card(s):
      • 5700 XT

    Re: Brain Teaser

    Quote Originally Posted by Lucio View Post
    Therefore the conveyor belt has sod all effect on the plane other than to make the wheels spin really really fast.
    Exactly, and the key to that is those magic, frictionless bearings which would provide no opposition to motion. It's like saying the plane isn't touching the belt at all.
    ____
    (='.'=)
    (")_(")

  13. #12
    jim
    jim is offline
    HEXUS.clueless jim's Avatar
    Join Date
    Sep 2008
    Location
    Location: Location:
    Posts
    11,435
    Thanks
    612
    Thanked
    1,639 times in 1,304 posts
    • jim's system
      • Motherboard:
      • Asus Maximus IV Gene-Z
      • CPU:
      • i5 2500K @ 4.5GHz
      • Memory:
      • 8GB Corsair Vengeance LP
      • Storage:
      • 1TB Sandisk SSD
      • Graphics card(s):
      • ASUS GTX 970
      • PSU:
      • Corsair AX650
      • Case:
      • Silverstone Fortress FT03
      • Operating System:
      • 8.1 Pro
      • Monitor(s):
      • Dell S2716DG
      • Internet:
      • 10 Mbps ADSL

    Re: Brain Teaser

    This is just basically twisting the normal teaser full circle so that the plane now does take off.

    As Lucio said, the conveyor belt has no effect. No matter how fast it moves the plane will still take off in perfectly normal fashion.

    They should definitely put some generators on the wheels though.

  14. #13
    Senior Member JPreston's Avatar
    Join Date
    Nov 2005
    Posts
    1,667
    Thanks
    5
    Thanked
    124 times in 74 posts

    Re: Brain Teaser

    That thread in the physics forum I linked to in the OP in the original thread has been going for four years now

    618 pages! And the answer should be obvious.
    Quote Originally Posted by Bertrand Russell

    The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Why is it easier to find bad stuff???
    By MrSnaffles in forum General Discussion
    Replies: 26
    Last Post: 14-05-2009, 09:15 PM
  2. So Corsair launch new modules...
    By DR in forum General Discussion
    Replies: 61
    Last Post: 26-11-2008, 01:45 PM
  3. The all new Brain Teaser thread..with knobs on!
    By 0iD in forum General Discussion
    Replies: 41
    Last Post: 22-10-2008, 04:15 PM
  4. Brain Teaser
    By TiG in forum Software
    Replies: 0
    Last Post: 27-05-2004, 12:25 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •