Episode 138: Soda Cup Killer

Air Date: March 24, 2010

A Styrofoam cup filled with soda, tossed from a car moving at highway speed, is capable of piercing another car’s windshield and killing its driver.

busted

Adam and Jamie first fired several different mixes of soda and ice out of an air cannon to measure which was capable of delivering the most force. They found that slush was the most effective mix. To simulate an oncoming vehicle, they built a test rig in front of the air cannon with a windshield and with Buster as the driver. In a test shot at 40 miles per hour, the cup was able to crack the windshield. At the full 60 miles per hour, the cup pierced the windshield, but did not retain enough momentum to be lethal to Buster. Finally, they decided to repeat the test using aluminum soda cans. While the cans pierced the windshield more effectively, Adam was unable to hit the windshield accurately enough to hit Buster. They also tried using a shoulder mounted air cannon, but still could not hit the windshield accurately enough. With only one windshield left, the Mythbusters fired at the windshield at point blank range, “killing” Buster. However, since the cup lacked the power to harm Buster, the myth was declared Busted.

A person can hang off the edge of a building or cliff indefinitely.

busted

The Build Team first tried to hang off the edge of a building with three inches of space to hold on to. All three members could only hold on for roughly one minute. They then reduced the grip space to one inch. Now Jessi could only hold on for thirty seconds, while Grant could not get a grip at all and instantly fell. Aaron, an expert, showed that he could hold on to an inch of space for roughly forty seconds and half an inch of space for fourteen seconds. However, nobody could hold on to the edge indefinitely. The Build Team concluded that the only way one could be saved in this situation is if help arrived very quickly.

A person can hang off the landing skid of a moving helicopter and successfully climb into the helicopter.

confirmed

Because hanging off of an actual helicopter was deemed too dangerous, the Build Team decided to simulate the experiment. They first tested the downward force generated by a helicopter to see whether it would affect a person’s ability to hang off the skid, but found that it would at most only exert 130 grams of force, which was negligible. For the experiment, they built a fake helicopter and hung it over a swimming pool for safety reasons. To simulate movement, they set up a large fan that could create winds of up to 95 miles per hour. Jessi, Tory, and Grant all took turns hanging off the skid and succeeded in climbing into the helicopter. Though a success, the Build Team was quick to point out that it was much harder than the movies would make it seem.

A person can single-handedly rescue another person who is hanging on a ledge.

confirmed

The Build Team members took turns rescuing each other from hanging off a ledge. They succeeded, but found it to be a difficult and awkward process.

20 Comments

  1. Tim I says:

    I have disparages with how the Cup vs. Car was done.
    First off: Were you in Britain driving on the wrong side of the road?
    Secondly: Who throws an un-opened can of pop out?
    I still think your results were correct, but how they were tested was done in ideal situations.

  2. chandra raj says:

    i want to know that how, wnen a bullet enter the body by a small hole but when comes out the body
    it would a big hole ?. is there any energy effect.

    • Brian says:

      There’s a tumbling effect, as with the rounds used by the military in an M-16 in violation of the Geneva Convention, BTW).

      And there can be a dum-dum effect, such as Travis dum-dumming (cross-hatching) the rounds In Taxi Driver.

      And finally, if the round is made from softer material, it tends to expand upon impact making the large exit wound.

  3. Tim Hyder says:

    I think they shoulve tried milkshake and as thats heavier then slush, it might crack the windscreen

  4. Steve says:

    Regarding the cup vs windshield item, I’m wondering whether using an iced drink with large pieces of ice instead of the slush drink might be more dangerous. While it might pack a little less kinetic energy, there’s a chance that some solid pieces of ice might get through to do some damage. A piece might catch the driver or rider in the eye.

    The slush drink seems likely to largely dissipate into a spray upon impact, blunting any direct damage to the occupants.

    Nonetheless, I also suspect that the largest danger is from the damage to the windshield and a probable dangerous reaction by the driver, particularly an inexperienced or inattentive one.

  5. Phillip C says:

    Re: Soda Cup killer.
    For a laminated windscreen I agree the Myth is busted. However what you didn’t test was whether the same would be so for a non-laminated windscreen. I don’t know about USA but in countries like Australia laminated screens have only been common for the last 30 years so it is highly possible that an early model car built in the 60′s or 70′s could still have a non-laminated screen.

    From what I saw in your show I think the soda cup would go straight through a non-laminated screen and could even give fatal injuries and thus confirm the myth.

    I think you should retest with a standard toughened glass screen.

  6. max says:

    I would like to know the amount of relative airflow and the effect this has on the force exerted on the person. A helicopter hovering close to the ground will require less power than when hovering out of ground effect.

  7. Natalia says:

    The problem with windsheilds and them being pierced is the way their made. It’s basically two pieces of glass with a durable plastic inbetween which is almost impossible to tear. Trust me we’ve tried as in the local search and rescue crew took a sledge hammer to a car windshield to try. The glue that kept the window in place gave before the glass was pierced.

  8. Blair says:

    The slush cup out the window on the highway was completely flawed. A real windshield forms part of the structure of the vehicle and is glued in with urethane your windshield was taped in and the frame was too flimsy allowing the windshield to flex and pull away from the frame.

  9. Dover says:

    Agree with the results except one item…
    Assuming equal volume: the soda with ice should have less mass than the one that is pure liquid, since the ice has lower density than the water displaced?? Thoughts??

    BTW I do love your show!!!

  10. MossMan says:

    Adam & Jamie,
    I love the show. Jamie, I want to know who made the jacket that you were wearing in the “Soda cup killer” episode. I want one!
    Thanks.

  11. captain says:

    Ok so I saw what everyone else saw. But jamie and adam make the same mistakes myth after myth. Just like the frozen chicken vs unfrozen test this should have been more about the penetration not the force imparted on impact. I think if they retested the myth with soda or an uncarbonated beverage with a single large chunk of ice or ice pieces melted together that the liquid would allow the shattering / weakening of the windsheild but then the ice chunk would then have a much better chance of entering the cabin intact.

    The liquid and the cup would almost act as a sabote for the ice chunk(s) into the vehicle. The liquid would bear the brunt of the impact and disperse just like in the myth,shattering the windsheild and punching a hole in it, but the ice chunk that was floating in the liquid in the cup would keep moving at the higher rate of speed and enter the vehicle and cause damage to the driver.
    I hope they retest this one. I think it could be dramatically different results. The soda and ice had almost the same impact strength as the slush so the penetration by the liquid should be the same but with the added benefits of testing ice chunks or ice cube sizes. I know I get huge chunks of ice from fast food all the time so its not a huge stretch.

  12. Mike says:

    Did you subtract the mass of the steel plate from the impact result (I am assuming so)? I am guessing that some of the energy on impact would be lost in the thick steel plate in front of the load sensor thereby affecting the force of impact of the cup. The force of impact would be greater than calculated! You high falutin’ scientists feel free to correct me if I’m wrong!:-)

  13. Ken says:

    should have tested the foam cup toss with ice cubes as well as slush. while the slush does get the greater initial impact whats left to get past the windshield? at least an ice cube would have had a better chance of doing damage beyond the windshield

  14. Sara says:

    Heli:
    I’ve done heli-rescue training and work. Hover entry/exit is part of the training. Pulling yourself up from the skid is easy if your physically fit with no downwash issues. The biggest concern is not rocking the bird and causing a crash (be graceful).

    A 2-12 helicopter can knock me off my feet when it lands on a heli-pad (I’m 115 lbs). A smaller chopper messes up my hair but thats about it. You tube ‘slacklining’ video’s and look for the guys falling, grabbing the line with one hand, pulling themselves up, landing a backflip on the line… but then again… ask an office guy to walk up a couple flights of stairs and compare THOSE observations with the control group in this experiment.

    Hanging off a cliff:
    I’m a climber. Obviously, you can’t hang indefinitely because your using muscle to hold and muscle fatigues. Any climber I know can hold onto a very small hold for much longer than a minute. Last month at a party my friends and I were doing pull-ups off moulding over a doorframe (~0.5″). JS demonstrated a one armed pull up off the frame.

    The most influential variables I could see are grip strength and friction (surface texture, sweaty palms, etc.)

  15. Lindsay says:

    What I would like to see is if there is any differance in if the cup were paper. It could be just be where I live but I don’t know any place that ever use styrofoam any more.

  16. Lars says:

    What were the stickers they put on him? Some sort of cargo stickers with an ampul that would break if damaged.. What’s the name of it?

  17. Mike says:

    Regarding the windshield myth.. Using a brand new glass is kind of non-real experiment.. I would suggest to use an aged one or even an already cracked one instead.

  18. kcom says:

    It seemed to me their presumptive impact speed of 130 miles an hour was way overdone. Two cars crashing head on at 65 mph each will have a relative impact of 130 mph but it seems to me once you throw the cup out of the window it will rapidly decelerate. By the time it crosses the distance to the oncoming windshield I would guess it’s forward speed is significantly reduced and the relative impact speed significantly reduced as well.

  19. Katrina says:

    Hi, i was wondering about the soda cup windshield thing. Since your vehicle and the other vehicle were traveling the same speed would the speed of the cup double? Instead of the cup hitting at 40 mph like you were traveling would the oncoming vehicle make the cups speed accelerate or stay the same speed? me and my boyfriend had disagreements of that.

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