PROJECT

JOHN WICK CHAPTER 3 - PARABELLUM

      The John Wick franchise features Keanu Reeves performing miraculous stunts and creative ways to kill the bad guys. These movies are the type you can always count on if you like action movies. Chapter 3 is the longest out of the films and it seems they never run out of ideas for how John Wick can get out of sticky-situations. I really like these films because the physics behind the action are always pretty accurate for the most part. There are dozens of scenes that demonstrate realistic physics but this one stood out to me in particular because other movies always get it wrong. 

Underwater fight scene in John Wick CH. 3

In most action movies where a gun is being fired under water, the bullets seem to be just as deadly as they would above water. To examine how accurate the distance the bullet travels in the movie we must know how far a bullet would travel normally. 

In order to compare the distance a bullet can travel in the air and in water we will need to know the drag force acting on the bullet. John Wick uses a P30L pistol which fires a standard 9mm bullet. 

The drag force can be found using the equation 

   

 = Mass density

Air= 1.255 kg/m³

Water= 997 kg/m³

(Water's density is much more!)

= flow speed of the bullet

The initial velocity can be used which is 380 m/s from a P30L pistol. 

   = frontal area of the bullet

Standard frontal area of a 9mm bullet is 
4.8x10^-5 m²

       C_d = drag coefficent
I got 0.149 from a website about the specifications of a 9mm bullet 

After solving:  

Drag force can then be used in Newton's 2nd Law Equation F = ma to find the acceleration(deceleration) of the bullet due to drag. 

Using 1D Kinematics we can now find distance:

The distance traveled underwater is significantly less than in the air. This proves that bullets are almost useless underwater. 

Actual pistol fired underwater in slow-motion

       The clip above is actual footage of a 9mm being fired in a swimming pool and the results are pretty close to the movie. The movie actually looks closer to the result of 1.05m which we got from the specifications of the P30L pistol John Wick uses. The small explosions behind the path of the bullet are shown in the movie as well. The high pressure pushes the bullet out of the gun, but there is extremely low pressure behind the bullet due to the high mass density of water. This causes a vacuum that boils the water and creates bubbles exploding behind the path of the bullet. 

       One issue that the movie got wrong is the fact that there are several rounds fired in the scene. The Mythbusters did a test to see if a pistol would actually fire underwater and how far a bullet can go before it is non-lethal. When they tried to fire a second round underwater it jams because the casing is never ejected. The reload mechanism of a pistol relies on pressure to eject and when there is extra pressure from the water it is unable to load another round in the chamber. 

Conclusion:

      John Wick Chapter 3 captures what an underwater gun fight would look like very well. It almost seems as if they recorded actual underwater footage to record this scene and I wouldn't be surprised if this were true. Overall I give this movie a PGP because it has some pretty flawless physics behind each scene for the most part.