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This week Rev. Smith asked: “In Die Hard, do you think if Hans Gruber had fired his gun while falling he could’ve struck Holly or John?“

EXCELLENT QUESTION! I always wondered why he didn’t at least TRY to shoot ’em while falling.

Well Jon does a pretty great job answering the question (although he does take a few easy shortcuts, like assuming the villain, AKA Hans, is spherical even though he’s totally not):

Assume a spherical villain falling straight down.

Gravity accelerates an object at a rate of 32.174 ft/s^2 , so the downward velocity of the villain after t seconds in ft/s is 32.174 * t.

Distance traveled by a falling object is (1/2) * 32.174 * t^2 .

Hence, after 5 seconds, the villain is traveling at about 160.87 ft/s, which is not quite terminal velocity (around 180.45 ft/s), and has traveled 402.175 ft.

Now assume the villain fires straight up and is using .45 ACP FMJ ammunition. According to Wikipedia, that ammunition has an initial velocity of 830 ft/s with a test barrel length of 5 inches, and a mass of 15 g.

Since the villain and gun are traveling at 160 ft/s, the actual initial velocity of the bullet would be 670 ft/s.

Assume the bullet incurs no wind resistance. The same free-fall equations apply to decelerating the bullet.

Just eyeballing it, it would only take a bit over 0.6 seconds for the bullet to reach the villains starting point, and the bullet would only have decelerated a bit over 19 ft/s in that time. The bullet would still be traveling at about 650 ft/s, and at 15g would possess about 294 J of kinetic energy, compared to 477 J possessed by a round fired from a standstill.

After 5 seconds, then, the kinetic energy of the bullet would be decreased by about 40%. I’m guessing that would still be enough to injure someone, but I’m not sure.

What if the villain fell even further? He would reach terminal velocity of about 180.45 ft/s after about 5.61 seconds and a distance of 506.03 feet, and would continue at that velocity. A bullet fired at terminal velocity would have an initial upward velocity of about 649.55 f/s.

An object initially traveling at 649.55 f/s would take about 20.19 seconds to completely decelerate, and would have traveled about 6,557.64 feet.

The villian would fall 506.03 feet in 5.61 seconds before reaching terminal velocity, and could cover the additional 6051.61 feet in about 33.54 seconds at terminal velocity.

That means if the villain fell for just over a minute before firing back up, Bruce Willis could reach out of the window and pluck the motionless bullet from the air.

Dude. That absolutely deserves to be this week’s Answer of the Week. Both Jon and Rev. Smith get a $25 gift card for Pagliacci Pizza. Congrats, sirs! I suggest you enjoy your prize while watching Die Hard. Because it is one of the best cinematic achievements of all time.

(If you have a different theory on whether or not Hans could’ve hit our hero while falling several stories to his death, head over to Questionland and share your smarts with the world!)

Megan Seling is The Stranger's managing editor. She mostly writes about hockey, snacks, and music. And sometimes her dog, Johnny Waffles.

13 replies on “The Best Question to Ever Be Asked on Questionland!”

  1. I love it! The physics calculations are stellar, and “assume a spherical villain” shall now enter into my lexicon.

  3. psh…Hans Gruber. What a pussy. Falling to your death didn’t stop Billy Score (Henry Silva) shooting at Burt Reynolds in Sharkey’s Machine.

  5. The last sentence alone is worthy of a free pizza. Have you guys considered giving out drink vouchers for local bars? Questionland would be on fire.

  7. 6500′ is over four times the height of the Sears Tower, the tallest building in the world at the time the movie was made and more than twice the height of the world’s tallest building ever, the Burj Al Whatever just completed in Dubai.

  9. That’s amazing. I love it.

    As to the script, I am an expert at suspending disbelief but I find it very out of character that Hans didn’t immediately begin pulling the trigger ’til it clicked. FWIW.

  10. Plus, it would have made for a really comical scene at the climax of an action movie to show Bruce Willis and Bonnie Bedelia chicken-heading around flying bullets while looking over the edge of a sky scraper.

  11. Interesting math, but incorrect.

    (1) Humans are NOT spherical. They fall at different speeds, depending on their angle to the wind (we’ve all seen videos of skydivers all spread out like spiders to slow their fall). The terminal velocity of a falling human is around 65 miles per hour (ask any skydiver).

    (2) So even if our buddy Hans reaches terminal velocity, there is enough extra muzzle velocity in a .45 to do damage.

    (3) Every action has an equal and opposite reaction. That means Hans only gets one shot while in free fall. The recoil of his first shot would set him spinning, making any subsequents shots completely randomly aimed.

  13. @11

    Interesting corrections, but incorrect.

    1) “Assume spherical villain…” If you want to do the fluid dynamics calculations to calculate the drag coefficient that Hans possesses as he falls to his doom, be our guest. If not, let’s just keep assuming he’s spherical.
    And I asked my skydiving friend “Wikipedia,” about reaching terminal velocity and this is what he had to say, “…the terminal velocity of a skydiver in a free-fall position with a semi-closed parachute is about 195 km/h (120 mph or 55 m/s) -Huang, Jian (1999). “Speed of a Skydiver (Terminal Velocity)”. The Physics Factbook. Glenn Elert, Midwood High School, Brooklyn College. http://hypertextbook.com/facts/JianHuang….

    2) You’re making the assumption that gravity doesn’t exist to slow down the ascent of the fired bullet. You’re also assuming that he fires the bullet right when he reaches terminal velocity, he’s not. The bullet that Bruce Willis plucks from mid-flight has been fired after just over a minute from entering free-fall, not at the moment when Hans reaches terminal velocity.

    3) This would be true if Hans’ arm was a rigid structure attached to his center of gravity, but it’s not. Unless he was firing from his shoulder (like with a rifle) this would likely not happen. His arm would absorb most of the recoil from the pistol.

    Reading comprehension is a bitch…

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