Would the Peasant Railgun work in 5e D&D?

Question

Like in the question, would that be mechanically possible, according to the core rules, and working on the assumption that GM wouldn't just say "NO" due to the sheer stupidity of it. Also I am concerned about the damage such a weapon would deal, as well as applications to transport things.

To describe how it would work (taken more or less from 1d4chan):

1. Hire a ton of peasants; let's just say that it is two thousand two hundred and eighty. Line them up in single file; this will form a chain of peasants two miles long.
2. Buy a ladder. Just buy a standard, ten-foot ladder. Disassemble the ladder into a bunch of rungs and a pair of mighty ten-foot wooden poles. Hand a pole to the peasant at the back of line.
3. First round of combat. Peasant at the front of line readies an action to throw the pole at the enemy. Every peasant behind him readies an action to hand the pole to the peasant in front of him.
4. Next round: peasants fire off their readied actions, passing the pole two miles down the line and hurling it in six seconds or less. Pole accelerates to the speed of 1188 miles per hour, or Mach 1.546875 in dry air, at 20°C/68°F, at sea level on our planet.
5. Peasant Railgun can be reloaded and fired in less than 12 seconds.
6. [SKIPPED]
7. A hit. Now there are two possibilities:

• You actually threw a 10 foot pole: Our mass was 3.17514kg (7 pounds, as the PHB states a 10 foot pole weights), our speed was 536.448m/s (1200 miles an hour). The final kinetic energy was around 455,004 Joules. This is similar to 109g of TNT, or around half of a stick of dynamite. And now to hit someone with that.
• You threw something else. Or more specifically, someone else: A medium-sized dwarf would be able to fly around 18 miles with such starting velocity, if we ignore air friction. Of course, he is medium-sized, and there could be problems regarding handling medium-sized creatures by medium-sized creatures, so we pack a bag of holding full of those, and then launch.

Answer 1

The peasant railgun does not work under the rules of 5e

The whole trick of the peasant railgun, cool as it is, is that you frame-shift between the technical artifact of how to procedurally handle the actions that all happen at the same time in a combat round with constructs like Reactions, and the physics of how things work in the real world.

What would happen is that you had your long row of peasants, all passing on the pole as their Reaction, and at the end the last peasant would receive the pole. But there is no acceleration of the pole due to this, as the rules do not support that. You would have a peasant with a 10-foot pole. He could throw it as an improvised weapon, making an attack roll with his normal Strength bonus.

As per the Improvised Weapon rules (PHB, p.147):

An object that bears no resemblance to a weapon deals 1d4 damage (the GM assigns a damage type appropriate to the object). If a character (...) throws a melee weapon that does not have the thrown property, it also deals 1d4 damage. An improvised thrown weapon has a normal range of 20 feet and a Long Range of 60 feet.

D&D is not a physics simulation. If you exploit the approximation of reality the rules provide in the first part of your railgun, you need to stick to it through the end.

P.S. Transporting and throwing a dwarf with a bag of holding would not work for two reasons at least: in addition to the reason above, removing the dwarf from the bag takes a full action. A peasant would not be able to both remove the dwarf and throw the dwarf (an attack, also an action) in the same round.

Answer 2

There's a third option. You have computed, at best, the average speed. It can simply arrive at the final peasant at velocity 0. Much as you'd expect to receive any object being just handed to you. Nothing in the game mechanics or reality requires velocity to be non-decreasing throughout handoffs, or at the final handoff in particular. The final peasant has nothing more than the normal mechanics for a thrown attack at his disposal, with an improvised weapon in this case.

If this isn't clear, imagine you drive for one hour and travel 40 miles and stop. You then sit around doing nothing for an hour. Over that two hour span, you average 20 miles per hour. But at all points during that last hour you were moving at a rate of 0 miles per hour. Your pole or what have you is the same: it ostensibly travels at high velocity for some bit of time, but it can then slow down and have little to no velocity during other bits of time.