Falling Dire Bear

[youspoonybard]

What's terminal velocity for a bear, though?

It's different than a human because of their density and weight distribution, right?

 

[CalrinAlshaw]

What's terminal velocity for a bear, though?

It's different than a human because of their density and weight distribution, right?

Believe it or not, the terminal velocity difference between a marble and a bowling ball is the same. Now, if the bear had large flaps of skin acting as a parachute, I'd say yes...but it doesn't.

Only things that can cause more friction than normal (Wings, Feathers, etc.) can bypass terminal velocity.

CalrinAlshaw

 

[JiffyPopTart]

Another useless bit of physics I will throw into the fray...

If you WERE a druid who was a bat who was going to be changing into a bear and crushing someone, you wouldn't be flying along in a straight line parallel to the ground when you cut off your engines. You would instead approach the maneuver like a dive-bomber by diving straight down at the target and THEN changing forms.

Of course you could then argue that you are already moving your maximum flying speed, so your calculation of how fast you are going when you hit will start at whatever speed you can fly at instead of zero.

DS

 

[Spatula]

Shouldn't the Feet/sec bit go 32, 64, 96 ... instead of 32, 48, 80 ?

The Feet/Sec column appears to be derived from the Total Distance column, which is the result of the distance equation. After 1 sec you've fallen 16 feet. After 2 sec you've fallen 64 feet. So over the course of the 2nd sec you fell 48 feet... in other words, 48 feet/sec. Rather than your velocity at the end of the 2nd sec, it's your average velocity during that second.

Although it seems the initial velocity should be 16 feet/sec instead of 32.

 

[hong]

Crush: A flying or jumping dragon of at least Huge size can land on opponents as a standard action, using its whole body to crush them. Crush attacks are effective only against opponents three or more sizes smaller than the dragon (though it can attempt normal overrun or grapple attacks against larger opponents).

AR

Which, for a Colossal dragon, maxes out at 4d8 damage. That's what I'd use as a guideline if anyone else wanted to pull a similar stunt, instead of the terminally silly DMG rules for dropping things on people.

Terminal? Geddit? Terminal? Ah, heck.

 

[green slime]

Another useless bit of physics I will throw into the fray...

If you WERE a druid who was a bat who was going to be changing into a bear and crushing someone, you wouldn't be flying along in a straight line parallel to the ground when you cut off your engines. You would instead approach the maneuver like a dive-bomber by diving straight down at the target and THEN changing forms.

Of course you could then argue that you are already moving your maximum flying speed, so your calculation of how fast you are going when you hit will start at whatever speed you can fly at instead of zero.

DS

If you were a bat you wouldn't be flying in a straight line; Bats flit about something insane.

And you are still asuming your target is unawares, and stationary the entire time you are falling. Remember you didn't want to try this close to the ground, for maximum impact.

Given you have to fall approxiatemately 2 rounds to reach terminal velocity, and have then fallen at least 1000 feet, it can't be an easy manuever at all.

 

[Lamoni]

I just had a few comments to make...

First of all, I agree that it should be handled like a dragon crush attack. There is no real difference so if you wanted to use the falling weight rules, any dragon could wipe out player parties without ever using any standard attack or spell. I think that would increase the challenge rating of dragons by at least 20. It would go like this...
dragon makes crush attack: 2,063 damage to Player 1 (dies)
Players attack dragon, inflicting some damage.
dragon makes crush attack: 1,985 damage to player 2 (dies)
Players attack dragon, doing much less damage.
Repeat until party is dead, or they flee with a teleport spell. If the dragon does get hurt, it could fly/teleport away, heal itself and return to finish off the party. The party will run out of true resurrection spells before the dragon runs out of heal spells... and the use of raise dead spells won't help much either.

The table illustrating terminal air velocity wouldn't have a constant acceleration. Acceleration starts at 9.8m/s^2, but gets less and less as you have to take wind resistance into account until at 10 seconds the acceleration reaches zero. (the table looks correct. I just wanted to reply to some of the questions regarding it)

With the swimming pool example, jumping on a silhouette of a person's head and shoulders wouldn't be near as difficult if you were typically 12 feet long and weighed up to 8,000 pounds (from the SRD on Dire Bear).

By the rules, you could make it work and it would be a deadly attack, but also by the rules, the dragon isn't given this option when it was specifically given a crush attack. I would use the dragon crush attack rules while accounting for greater difficulty in aiming plus the decreased weight. Dire bears are heavy, but not when compared to a colossal dragon.

 

[LazarusLong42]

The rules my groups tend to use, ARE consistent with physics, in that, you take more and more damage DUE to acceleration...
10 ft you take 1d6
20ft you take 3d6
Basically, you take 1d6 + 2d6 + 3d6 + 4d6 etc until terminal velocity...cuz you speed up. That makes potentially far falls extremely lethal. In our group, that makes people NOT want to fall, which is VERY good. Even though NO one wants to fall 200 feet in game, it makes that fall very painful...210d6 is NOT fun, the DM that rolled that stopped after that particular fighter took 150 damage I think it was around the 45th die of damage or something.

CalrinAlshaw

While this is an interesting way to approach things, um, this actually goes away from the physics. Think of it this way:

The distance fallen is proportional to the square of the time. (d=0.5a*t^2) The energy of your fall is proportional to the square of the velocity. (E=0.5m*v^2)

However, since the time of your fall is proportional to the velocity (v=a*t), the energy of your fall--which would determine the damage done--is proportional to the distance fallen.

(d is prop. to t^2 is prop. to v^2 is prop. to E)

Therefore, for once, D&D physics makes sense. Damage should be proportional to distance up until you hit terminal velocity.

(That terminal velocity will be smaller for tiny creatures than gargantuan ones is something not dealt with, of course...)

 

[Plane Sailing]

Believe it or not, the terminal velocity difference between a marble and a bowling ball is the same. Now, if the bear had large flaps of skin acting as a parachute, I'd say yes...but it doesn't.

Only things that can cause more friction than normal (Wings, Feathers, etc.) can bypass terminal velocity.

I don't believe that.

A ladybird (whose wing cases are jammed shut) and an elephant both face the same acceleration due to gravity, but the ladybird will have a lesser terminal velocity. That is why it would survive a 15ft fall without noticing it, while the elephant would almost certainly die.

Could you direct me towards evidence that the marble and the bowling ball would have the same terminal velocity?

The best source I've found so far is at NASA

http://www.grc.nasa.gov/WWW/K-12/airplane/termv.html (my emphasis in quoted text)

We can determine the value of the terminal velocity by doing a little algebra and using the drag equation. Drag (D) depends on a drag coefficient, (Cd) the air density, (r) the square of the air velocity (V) and some reference area (A) of the object.

D = Cd * r * V ^2 * A / 2

At terminal velocity, D = W. Solving for the velocity, we obtain the equation

V = sqrt ( (2 * W) / (Cd * r * A) )

Typical values of the drag coefficient are given on a separate slide.

The terminal velocity equation tells us that an object with a large cross-sectional area or a high drag coefficient will fall slower than an object with a small area or low drag coefficient. (A large flat plate will fall slower than an a small ball with the same weight.) And if we had two objects with the same area and drag coefficient (two identically sized spheres), the lighter object would fall slower. This seems to contradict the findings of Galileo that all free falling objects would fall at the same rate with equal air resistance. But Galileo's principle only applies in a vacuum, where there is NO air resistance and drag is equal to zero.

 

[Henry]

On a related topic, does anyone think it's broken that any human, no matter how good a fighter, can fall thousands of feet with no fear of death?

I think the "world record" for falling from great heights is some thousand feet (girl from an airplane crash) without getting hurt.

Vesna Vulovic, Russian airline stewardess, fell some 17,000 feet in a wrecked airplane, and lived, but broke pretty much every bone in her body.

An american jet pilot made another record of about 12,000 feet some years later when he ejected, his chute didn't open, and he landed in a snow-covered forest. He walked away with only a few scratches.

In regards to the "fall thousands of feet with nary a scratch, don't forget the massive damage save for taking more than 50 points of damage in one source, Fort Save DC 15 or death. So it's not necessarily "no fear." The idiot fighter, even if 20th level, who jumps off of a 200' cliff to get to the fight at the bottom will arrive about 70 hit points down, and possibly dead if he flubs his Fort save. If he has a high enough CON, AND that many hit points, he deserves to live at the end.

But if it bothers anyone, do what I do: make it 1d6 CON damage per 10 feet fallen. Tends to change perspective.