Shooting balls of different weights into Lego castle walls. The same Lego rubber band cannon is used for all shots. Enjoy! Making of the Lego cannon: • Building a Lego Tank (... Slow mo camera: Sony RX100 V (can record at 1000 fps)
There was no unnecessary attempt to get 10 minutes, no long intro about subscribing, no filler, no click bait, no voice at all. You delivered exactly what you said in a very entertaining way.
@@kiwi_2_official He’s not even a bot. If he’s a bot, then he would have a Mr beast pfp and a verified checkmark. His video will also look like “Who is (insert username here)?” or something similar.
Eh, people might think they're smart, but actual smart people wouldn't feel the need to show off their "intelligence" in a youtube comment. It's more like pit of circlejerking.
1:52 I really like how the initial blow of the ball didn't break the walls, but the recoil from the baseplate resetting back to its flat position flung the walls off of the baseplate haha
@@runtergerutscht4401 Not really, think back to high school physics class. One of the rules that's battered into your head is "any force will have an equal and opposite force applied to the object exerting the initial force". In any given impact, the ball is exerting force on the wall backwards (toward the lego man), causing it to either slow down or to cause it to go flying the other way. The walls accept the backward force spreading them throughout themselves and anything they're attached to, creating a downward force on the base. The downward force on the plate causes an upward force on the plate, causing one of two situations, either pushing the wall up, surrendering the wall to the initial blast backward by the ball, or the walls hold, allowing the baseplate to push off of the table, creating an upward force in the baseplate itself. (There'd also be a backward force on the baseplate, since it's attached to the walls until they pop off, but I'm going to assume that the baseplate was stopped from going backwards, somehow.)
Suggestion: - Add weight to the ground, so the energy is not lost in it - Double/Triple check when a marble fails, to see if it fully fails, before going on to a stronger one
Those U walls and supported walls models are a brilliant way to show how force transfers over a wall... in the slow motion, we can see that the pieces that took the biggest hits are actually the ones at the back, it's fascinating!
I suppose it could be viewed as them taking a hit, however I was considering net force and would say they had the most force transferred to them through the system. All of the walls pushed against each other on the axis of the hit, and those pushes were all equal. That meant when the ends didn't have something to push against them they'd fly away however they still pushed against the sections of wall that are still standing. Absolutely love this kind of interaction and am rambling a bit, sorry :)
There's another level you could go with the ball, but you're getting into very expensive territory. Tungsten carbide 15.63 g/cm³, ultimate level is iridium at 22.56 g/cm³
Actually, osmium is slightly denser. The original density calculations were off, and no one bothered to redo the test for a long time, long enough for it to be common knowledge that iridium is the densest.
I think this is because the cannon is limited by the maximum speed it can get the launcher to move. The balls all leave the cannon at similar velocities, so more energy is transferred to speed up the heavier balls instead of being lost in the cannon when the launcher hits the front. As the projectile mass approaches what the cannon is capable of moving, I think we'd see diminishing returns on how many walls it could breach.
The rubber bands are accelerating both the push bar and the ball. With the lighter balls more energy is going to the bar which is lost when it strikes the end.
data displayed at end of clip is even more interesting than test itself, the numbers resulting from the test are beautifully mathematically related to the mass of the spheres - and therefore to the kinetic energy. It would be awesome to check those 'bullets" shooted at speed generating enough force to penetrate wall (for the one made of steel), and than find out what will happen to the other ones at same velocity :D
Great observation! some quick data analysis reveals that the number of walls is approximately modelled by n=m*sqrt(x), where n is number of walls, x is the weight of the ball, and m is some constant coefficient. The coefficient m for the double wall was exactly double that of the quad wall, but the other coefficients didn't have any nice relations. For those curious, I plotted the transformation z=sqrt(x) (square root of weight) against n and got a graph that was roughly linear (I tried a few other transformations, such as logarithmic and cube root [single wall fit a cube root well], but square root seemed the best fit across the board). When you have the "linear" graph n=mz, you can calculate m by doing rise/run and compare the model to the actual values. The model for the double wall was the "nicest" because comparing theoretical values correctly matched the actual values (after rounding) 2.12035979898674 3.37485975740272 5.99728316967547 8.12035979898674 Obviously many things made certain points deviate from the trend, such as the discrete nature of n, the fact that the kinetic energy may not have increased the same for each ball (as the cannon would eventually reach a limit where the increased weight would absorb all kinetic energy of the elastic bands, meaning any extra weight would have the same KE), and the fact that the flexible floor absorbed some impact, to name a few things.
@@Wagon_Lord also - friction and resistance between the floor and walls resulting from the method of connection - push-fit. And in case of floor, other than flex i will assume also motion and friction wich will count as absorbent, different each time because of changing mass of entire structure dependant on number of used wall elements
@@Wagon_Lord I chose to only look for the first column because the number in the others are really small. Anyway I would like to test a model : The potential energy E0 in the rubber band, that will be given to what is attached to it is a constant (doesnt depend on the mass of the ball). The energy lost by friction with lego thing in contact withe the ball is also constant Ef1 = F*L where L is the length of the ramp. Let's say E0 - Ef1 = E1 (it's a constant). The energy lost by friction with the ball is proportional to its mass, Ef2 = k1*m (may be it's less than a proportional model but not more, because if the ball starts rolling in the ramp, the friction decreases). May be we can negelect this contribution. Then the remaining of the mass E1 - Ef2 will be given to the ball (E) and to the lego thing attached to the ball (E') that also moves at the same speed, proportionnally to each one's mass (m and m') : E/m = E'/m' and E+E' = E1-Ef2 E = (E1-Ef2)*m / (m+m') E = (E1*m - k1*m²) / (m+m') We can use this model supposing that the number of wall destroyed is proportional to E : n = (n1*m - k*m²) / (m+m') This model shows that there is an optimal mass to destroy the most walls (which is quite realistic, even though I don't know if a power between 1 and 2 on m in k2*m² isn't better than 2). I suppposed that the pulling force of the band was bigger than the friction. But the contrary is totally possible and this is where the model gives negative values. It should be n = max(0 ; (n1*m - k*m²) / (m+m')).
Would be interesting to see how the wide walls fare against multiple lighter shots, once the connecting bricks have been damaged/blown off I assume that the wall is weakened substantially at that point.
Damn, I can't believe one of these just popped up on my recommendations then I just zone out watching these relaxed because they're strangely therapeutically appeasing and satisfying to just watch - brings me back to get old Legos and constructs days but to the end the degree of ways I never thought possible lol - subbed and keep doing what you're doing - stay safe 😊👍
That little man is so brave. He was hitten many many times, crushed by walls in such a brutal way, and still he`s standing the ground again and proudly hold the flag !
It's interesting how there is such a difference in the outcomes between the last failure and the success. One might imagine only one wall remains standing, but often multiple walls remain in place despite each having fallen without the final support added.
I remember the days of eld where Knights were so chivalrous to one another, they allowed the enemy Ballista to get within 7 bricks of the wall before firing.
Very good video , I enjoyed it completely, and best of all: No annoying music, no annoying voice-over narration. Just pure, Lego Engineering and quality Slow-Motion footage 🥰☝🏻⭐️ 🥇 🏆
We used to make these back in the day, the draw was manual though, as this was the early nineties. We all built a fort, occupied it with the lego toons, and then wreaked havoc on each other. We called them smoothie guns because of the need to use the smooth tiles on the firing track. Good times.
reminds me of a downsized version of a slingshot crossbow I made once; perhaps the heavier balls deliver more energy as the rubber band is limited by it's contraction speed with the lighter weights.
So with the unsupported walls, going for double walls saves resources for the plastic and glass ball, and wastes them for steel and tungsten. Going above double wastes resources in all cases. In the end however, the real solution is engineering, as we can see with U-walls and supported walls.
Only for single shots. If there had been tests for multiple shots, double and higher actually saves resources, since the walls are more capable of staying in place.
Very great video, heads straight into the experiment while having very simple introduction. I enjoy destructive and simple experiments with legos like these, very cool! Keep it up!
Hey, I've got a suggestion for you. Making a full lego trebuchet that can launch a (insert heavy object) a fair distance. And tuning it to go as far as possible.
Interesting that 13 single walls is actually more resource efficient than 8 double walls for the same survivability (especially when you consider that 12 single walls was BASICALLY a survival) (Although obviously if you were to build this as an actual castle, you’d be getting effects more like the octa-wall, so a double layer in a 8x8 or 10x10 square would make for a pretty tough structure)
@@kiwi_2_official I'm not, but I'm probably not going to convince you. If I were a bot, what would I actually accomplish? Perhaps I'm just a regular person who speaks weirdly.
With just walls most efficient: Against plastic(1.5g) - double and quad(4 walls) Against glass(3.8g) - doubles(6 walls) Against steel(12g) - singles(10 walls) Against tungsten carbide(22g) - singles(13 walls)
Can you move the walls to middle of the lego sheet instead of on the edge? You can see the whole sheet move(bounce up absorbing part of the impact strength) each time after the impact.
Is there any way to pin the floor down to more accurately test the strength of the walls? Correct me if I’m wrong, but wouldn’t the flexing on the baseplate absorb some of the force of the impact? Or am I wrong?
I have to study for my physics test next week but suddenly had this video in recommendations... I'm sure that knowing how to protect from Lego cannon is more important than knowing Gauss theorem
I love how its just, plastic ball(casual, we chill), and then a marble(ouch, that would hurt if it hit me), and the smell ball(ok now this is an actual weapon), Tungsten carbide ball, *this time out loud* BRO SKI CHILL
I feel like these could be used as a great way to show how solid engineering solutions can save a lot of money and resources compared to brute force solutions. Very nice!
