Hey everyone! In the last video, I said I’d upload a follow-up video to reveal the answer to the floating boat + rock puzzle… But after thinking about it, I realized it’s simple enough to explain right here — so here we go!
Puzzle Recap: You’re in a boat, floating in a big container of water, holding a rock. You throw the rock into the water, and it sinks.
Question: Does the water level go UP, DOWN, or stay the SAME?
Correct Answer: The water level goes DOWN!
Here’s why — in simple terms: When the rock is in the boat, the boat sinks more due to the rock’s weight. That means it displaces more water, making the water level higher.
But when you throw the rock out, the boat becomes lighter and floats higher — so it displaces less water.
Now the rock is in the water, but it only displaces an amount of water equal to its own volume. Since rocks are heavy but don’t take up much space, they displace less water when submerged than they did while in the boat.
So overall — the water level drops.
Quick example to make it super clear: Imagine a heavy iron ball on a floating tray in a bathtub. When the ball is on the tray — the tray sinks more. Throw the ball into the tub — the tray rises, and the ball displaces less water on its own. Result? Water level drops.
Pretty cool, right? Let me know in the replies if you guessed it right! Thanks for participating in the quiz.
Engineering Made Easy
https://youtu.be/Ze0gYH21Ugw
Answer to the “Rock in the Boat” Puzzle!
Hey everyone!
In the last video, I said I’d upload a follow-up video to reveal the answer to the floating boat + rock puzzle…
But after thinking about it, I realized it’s simple enough to explain right here — so here we go!
Puzzle Recap:
You’re in a boat, floating in a big container of water, holding a rock.
You throw the rock into the water, and it sinks.
Question: Does the water level go UP, DOWN, or stay the SAME?
Correct Answer: The water level goes DOWN!
Here’s why — in simple terms:
When the rock is in the boat, the boat sinks more due to the rock’s weight. That means it displaces more water, making the water level higher.
But when you throw the rock out, the boat becomes lighter and floats higher — so it displaces less water.
Now the rock is in the water, but it only displaces an amount of water equal to its own volume. Since rocks are heavy but don’t take up much space, they displace less water when submerged than they did while in the boat.
So overall — the water level drops.
Quick example to make it super clear:
Imagine a heavy iron ball on a floating tray in a bathtub.
When the ball is on the tray — the tray sinks more.
Throw the ball into the tub — the tray rises, and the ball displaces less water on its own.
Result? Water level drops.
Pretty cool, right?
Let me know in the replies if you guessed it right!
Thanks for participating in the quiz.
2 weeks ago | [YT] | 3