AK-47 Underwater at 27,450 frames per second (Part 2) - Smarter Every Day 97 | Summary and Q&A

TL;DR

In this video, the host and his friends use high-speed cameras to observe and analyze the behavior of bullets fired underwater.

Key Insights

• 💦 Building an aquarium to contain the water proved unnecessary, as the focus was on keeping the water out during the experiment.
• 🚄 The high-speed camera reveals the presence of gas bubbles and the movement of the piston during the gunshot.
• 💐 The Bernoulli principle explains the low pressure and high flow occurring when the bullet pushes the water out of the barrel.
• 🫢 Cavitating bubbles, shock waves, and arrangements of gas and gunpowder create different visual effects during and after the gunshot.
• 🫢 The behavior of the bubbles and the visual effects observed can be explained by understanding the physics behind each component involved, including gas pressure, bullet velocity, and fluid dynamics.
• 👻 Collaborations between YouTubers allow for the creation of informative and entertaining content that reaches a wider audience.
• 🥡 The experiment takes place in a controlled and safe environment to prevent harm to anyone involved.

Transcript

Hey it's me Destin welcome back to Smarter Every Day. So I've been learning a lot about guns underwater, which is pretty cool. I mean, in the first video I learned all about what's happening back here in the action. But the problem is because of limitations in my setup I didn't get to see what happened when the bullet exits and goes into the water.... Read More

Questions & Answers

Q: What is the purpose of the experiment in this video?

The purpose is to observe and analyze the behavior of bullets fired underwater, specifically focusing on what happens when the bullets exit the water.

Q: How does the host overcome the challenge of triggering the camera underwater?

The host invites the Slow Mo Guys, who bring a Phantom v1610 camera that can reach speeds of 18,000 frames per second. This camera allows for capturing the underwater gunshots without the need for manual triggering.

Q: What is the significance of the gas bubble observed during the shot?

The gas bubble is a result of the piston venting after being pushed by the bullet. This short pressure impulse overcomes the springs and friction in the weapon, allowing it to cycle and shoot.

Q: What causes the oscillation observed in the bubbles?

The oscillation in the bubbles is a result of a phenomenon called the Rayleigh-Plesset Equation. It describes how bubbles behave under water and involves the bubble growing, collapsing, and then growing again due to pressure differentials.

Summary & Key Takeaways

• The host sets up an experiment to observe what happens when bullets exit and go into the water.

• The Slow Mo Guys join the host and use a high-speed camera to capture the action.

• The video reveals the presence of gas bubbles, the role of the piston, the oscillation of the bubbles, and the Bernoulli principle in the underwater gunshots.