[Youtube Review][Veritasium] 블록 사격 실험

(Recommended)Popular Videos : [Veritasium] 블록 사격 실험

 

This time, I will review the popular YouTube videos.

These days, even if it's good to watch on YouTube, sometimes people skip it or don't watch it if it's too long.

When you watch Youtube, do you scroll and read the comments first?

To save your busy time, why don't you check out the fun contents, summary, and empathy comments of popular YouTube videos first and watch YouTube?

(Recommended)Popular Videos : [Veritasium] 블록 사격 실험

https://www.youtube.com/watch?v=vWVZ6APXM4w

 

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Playtime Comments : [Veritasium] 블록 사격 실험

No***********:

0:50 My guess is it's not going to go anywhere, because due to the twisting motion, both sides of the block will end up hitting its holder, basically causing it to have too much friction to fly up in the air.

 

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Top Comments : [Veritasium] 블록 사격 실험

BB***************:

Amazing experiment. Righto, we're off out shortly to shoot our answer, with a bit of slow mo to explain it! Watch out for it…

Su**********:

Same height. Energy is not conserved in an inelastic collision (bullet remains stuck inside the block). Only Momentum in the vertical axis is conserved in the process. So the actual position of impact doesn't matter. Only momentum in the vertical axis before and after the collision should be equal.

As***********:

Never imagined Minute Physics to look like that O.O

Re************:

That's neat how he is meeting up with other science channel YouTubers

Al*******:

Thought you were going to block a bullet, Misleading title!

XD

IL*********:

I've thrown framing lumber cut-offs from roofs onto concrete before and I've noticed that when one side lands first, it can bounce up several feet, but when it lands flat, it doesn't move very much afterwards.
Now I don't know if this can apply to this scenario, as when a block is thrown on concrete it can be induced to go into a roll that ends up catapulting it, but because this is Veritasium and the answer is always the unexpected one, I'm going to say it goes higher.

Ma***************:

Who else on a non computer device

En********:

ooh cmon this is unfair, im on android, cant see annot :(

si********:

Did this make anyone else smile like a fool at his/her screen and garner a lot of awkward stares? I always greatly look forward to new veritasium posts!

Ge******:

i think it'll reach the same height. the angular momentum energy comes from the placement of the rifle. if doesn't take away from the translational energy.

am******************:

Hi man, i wanna thank you for beautiful facts that you find and making good questions about them I'm from iran and our teacher show your videos in our class and ask us to predict the answer and if we answer correctly he gives us mark,you made a very good challenge for our class thank you from bottom of the heart All the best

Ja*********:

When the bullet strikes the block off-center, the block begins to spin. As the block begins to spin, the block acts as a lever and the nail pushes downward against the plexiglass stand. The plexiglass structure sits on solid ground, so as the nail pushes downward against it, the effective result is the nail is helping to launch the block upward (just as anything that gives the earth a downward shove will itself experience an upward acceleration). Hence the spinning block will reach about the same height as the non-spinning block, even though some energy is used toward spin acceleration instead of a directly-upward acceleration. To prove my theory, you can do the experiment again, removing the plexiglass stand at the exact moment of bullet contact (I'm not sure how this could be done). Or more easily you can suspend the block using a squishy support structure instead of the rigid plexiglass. If you do this the result will be much different, and the spinning block will not go as high as the non-spinning block.

Th**********:

Those two guys in the car are sitting kinda weirdly. Why?

Pr*********:

I tried same with a pen but a rotating pen covers half height as much when force is applied at centre

Pe***:

I know I'm late to the party watching all of these, but I agree with the last 2 guys. Now, depending on HOW you measure the height - the highest point that any part of the block will reach, the highest point the entire block has to clear, or the highest point that the block's center of gravity will reach - if it's the first scenario, then it will go higher, since the spinning block will have it's longer side spin and reach a higher point (assuming only a little bit of the energy goes into spinning the block and the rest will continue to work on raising it), kind of like a jumping man would reach his max height, and then reach with his arm even higher. For the second and third scenario, since some of the energy will translate to angular momentum, there will be loss of energy in the "up" direction because it will go toward spinning the block, thus, the block will reach a lower height.


Now, knowing how your videos usually go, I am aware that I will be likely proven completely wrong.

sh**********:

love you love this love all of those channels thank you for making my life interesting

Ro************:

Uhu!!! Errei!!! Errei!!!! Errar é muito mais divertido que acertar pois vou aprender algo!!

Aliás acho que todo cientista adora quando descobre que está errado!!

Za*************:

I love these collabs.

o*:

Where does the energy go? Does the spinning block heat up less from the bullet?

Cu********:

My instincts say it will go higher because spinning things look scary and I don't like them anywhere near me.

My logical side says it won't go as high, because it's losing as it spins.

Which side is right? I honestly have no idea.

Ke************:

So, i used some estimations, did some math and came to the result that the blocks rotational energy is close to half of the potential energy (j did it at 2am so maybe not that accurate ^^) I can only asume that there are some really nasty gyroscopic effects are envolved OR that the efficency for the transfer of mechanical energy is higher in the second case because the block can "move faster away from the bullet" by the rotation around the nail and so gets more mechanical energy from the bullet.

Sh*******:

VERITASSIUM !! IS THE ANSWER COMING OUT ALREADY? I'M DYING OF CURIOSITY

Li**:

Just simple conserve of momentum. No mystery at all.

ra*************:

coanda efect.

Br*****************:

Er... why?

Ah**********:

I feel ur pain, me too

R0******:

My idea is that when the block is struck in the middle, the energy going into fracturing the block is spread out evenly and the remainder of the energy is converted to gravitational potential energy. But in the second case, the energy to fracture the block is spread unevenly as it is shot in the side (more block to the left than right). This uneven distribution introduces a moment in the block causing it to spin while the block and the remainder still pushes the block as high as before.

Ma**********:

My first impression:
Same energy goes in,
off-center impact causes rotation, rotation "eats" a bit of the energy.
off-center should go less high ( as measured for center-of-mass of the block!)

Pe*************:

Use different materials on the blocks with the same weight but different density?

K*:

I'm thinking when hit dead center all the available energy from the bullet is used to build inertia into one direction and act on the full weight of the block. When hit from the side, the nail acts as a fulcrum and only requires half the energy to set the object in motion. The left over energy is converted to rotational energy. So the same force was applied but was used by the block differently.

Bl************:

If you cannot see the rotation of the left block, you should check the video again. It rotates around the other two axes, just much slower.

aa**********:

Did anyone tell you that you look like a skinny Ben Affleck. Not a bad thing but I'm just saying. Anyway keep up the good work!

Da**********:

So... my guess is that they'll go to different heights. My reasoning is that you're scientists, not gun people, so you're probably using something like cheap Remington ammo which has a lot of variance in the loaded charge. ;)

de*******:

I realize that. I meant it only as a matter of safety, when they move the bullet strike to the edge of the block it's only mere cms away from missing if anything goes wrong. I will however accept your answer of "because science," you can never come back against that.

Ni*******:

The block that was shot in the center was slightly harder to lift than the block shot on the side. The block shot in the center had to be lifted all at once, trying to pick up a steel I beam in the middle is a lot harder than lifting up the same beam from a single end. The extra energy of the spinning block came from the bullet not having to work as hard at the beginning to initially get the block moving. This is my theory anyway.

Mi********:

Higher, done!

Ca*********:

I think, the one with the hit at the edge would penetrate a little less, and starts rotation earlier than rising [ i.e. some of its energy is already converted and stored as rotational K.E.

Momentum conservation would give the best results

And I would suggest if the energies of deformation are involved, never include energy equations in solving such problems


And, also I predict that if it is performed with iron block and iron [musket balls] it would lead to different results as iron will not have that much deformation

St***************:

Okay so there's a few things to consider here. The block is balanced on it's centroid, meaning that being shot there provides the most resistance to an upward velocity. If the block is shot to the side of it's centroid, then much more vertical velocity will be imparted on the side that was shot. This means that that side will begin to accelerate upwards faster and pull the other side along with it. Because you've got a greater force pulling the block upwards, the other half of the block will also accelerate upwards faster.

My hypothesis is that shooting the block on the side will make it jump higher

ha*************:

To the same height, because the upward linear momentum of the bullet just before it collides with the block needs to be equal to the upward linear momentum of the system just after collision, so the block acquires the same upward velocity just after the collision. The height to which the body rises depends on the upward linear velocity soon after collision. However when the point the bullet hits is horizontally away from its center of mass the collision produces an instantaneous torque giving it some angular momentum. So the block will be rotating about its center of mass in addition to its upward motion acquiring more kinetic energy from the bullet than earlier.

 

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[Veritasium] We gathered comments about popular videos and looked at them in summary, including play time, and order of popularity.

It's a good video or channel, but if you're sad because it's too long, please leave a YouTube channel or video link and I'll post it on this blog.

 

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