The physics of big sack over beautiful wall

[struggle4progress]

https://media.wired.com/photos/596929bb2429f82ff6dd991d/master/w_532,c_limit/spring_2017_sketches_key2.jpg

RHETT ALLAIN
SCIENCE
07.14.17 06:31 PM

Suppose someone builds a wall. A great and tall wall that is both impenetrable and beautiful. Who knows—maybe it's even solar powered. This wall stands 10 meters tall and goes on and on and on.

Now suppose someone wants to toss a bag of stuff over that wall. A big bag with a mass of, oh, 60 pounds. (I will say 27 kilograms, because kilograms are better.) How much force must be applied to get this bag over that wall? And what happens if the bag bonks someone on the other side? ...

... This would require an average throwing force of 2,646 newtons, or almost 600 pounds. That makes this one tough sack-throwing hombre, someone not to be messed with.

But wait! But what if that hombre hurls that sack over that mighty wall and bonks someone on the head? ... Well, the physics is exactly the same, but backward. If you caught this sack on the other side with a catching distance of 1 meter, you would need an average force of 2,646 Newtons. If it hit you in the head, it might stop over a much shorter distance of about 0.25 meters. In this case, there would be an impact force of 10,584 newtons. Bam. That would hurt. Hopefully someone gives this massive magnificent wall some windows so you can see the sacks being tossed over ...

https://www.wired.com/story/trump-heroin-wall-physics/

[csziggy]

1. What you need is a trebuchet throw stuff much farther

Away from the wall at a much higher velocity.

[longship]

9. Easy Peasy with a trebuchet!

You could pitch a car over such a wall with a trebuchet.

[grantcart]

13. Everything you can imagine has already been done

Drones, Light aircraft, submarines.

[Brother Buzz]

2. Border Patrol Agents are going to start moonlighting as baseball pitching scouts

[ismnotwasm]

3. Hahahaha! I love physics

K&R

[Initech]

4. If Trump builds a wall, someone is going to build a catapult!

[ProudLib72]

6. Hopefully they put him in it!

[Initech]

11. Like this?

[ProudLib72]

12. Sort of

I was thinking more of a poorly designed catapult that launches him straight INTO the wall instead of over it.

tRump brand pancakes anyone?

[smirkymonkey]

5. "What if we built a giant wooden badger?"

[mr_lebowski]

7. After Trojan Rabbit has been taken into Castle ...

Arthur: "So, what happens now?"

Knight: "Come nightfall, Lancelot, Bedevere and I ... leap OUT of the Rabbit, catching the French not only by surprise, but completely unarmed!"

Arthur (glancing around to see Lancelot & Bedevere still at his side): "Ummmm ... WHO ... leaps out of the Rabbit?"

[gratuitous]

8. Hey, give President Trump a break

You expect the man to know what it takes to lift 60 pounds? Those soft little hands of his get a maximum workout stabbing out his tweets.

[Solly Mack]

10. Hehe

[3catwoman3]

14. You explained it much more scientifically than I could...

...have (biology is my thing, not physics), but we came to the same basic conclusion. This scenario seems impossible. I doubt that most ordinary humans could throw even a 10 pound object over a 10 foot wall. Never mind 60 pounds over a higher barrier. Ain't happening.

[Adrahil]

15. That's a wierd way to calculate this....

As the author notes, the force is applied over some distance, so it's not like all that for e is exterted all at once. Besides, a better, more accurate way to calculate what it takes is to use the ballistic equations of motion.

[struggle4progress]

17. You need to know the total energy, which at any time during the trajectory

is the sum of the kinetic and potential parts.

The total energy initially added is a product (Force x Distance), involving the length over which the source is actively doing work on the sack and the actual force generating the acceleration: a larger force is required if one wants to impart a certain kinetic energy over a shorter distance than if one wants to impart the same kinetic energy over a longer distance. And in the same way, decelerating an object from a given speed to a complete stop over a shorter distance involves more force acting on the object than decelerating that object from the same speed to a complete stop over a longer distance: think of the difference between dropping an egg from a short height onto a solid wood floor, as opposed to dropping the egg from the same height onto a deep but loose pile of shredded paper

[Adrahil]

18. Total energy isn't that usful in this case...

You can generate a lot of energy by exerting a small amount of for e over a large period of time. But if you are throwing a bag over a wall, you cannot exirt the force once you throw it. More useful is finding the velocity required when you release the bag. If you know how long it takes to swing the bag to the release point, you know what acceleration, and therefore the force required.

But honestly, a trebuchet or pneumatic cannon would be way more useful

[MiniMe]

16. You would lose control over that bag if you could possibly "toll it over the wall"

tRump should understand that, you aren't going to toss it unless you can make money off of it

[Jim Lane]

19. You don't understand Trump's business brilliance.

He'd get investors to put up the money to buy the drugs, telling them they'll be repaid out of the proceeds of the sale in the U.S. He'd pay himself hefty fees for buying the drugs, for buying the sack (which has a big beautiful TRUMP logo on each side, generating a licensing fee for use of the name), for packaging and transporting the drugs, and for tossing the sack. If the drugs can't be recovered and sold, well, it's the investors who take the loss.

So he's just assuming that some Mexican drug lord would be smart enough to do it that way, too.

[MiniMe]

20. ...

How silly of me not to see his master plan