If I'm ×4 strong and my club is ×4 heavy, do I hit you with ×16 force?

[Raekai]

This is more physics than GURPS, I suppose, but I want to know because of GURPS. It's more of a thought experiment, but it's because of GURPS that I have these thoughts, which means I should really blame the GM who introduced me to it in the first place.

You have ST 10 (BL 20) and a knobbed club that weighs 2 lb.

I have ST 20 (BL 80) and a knobbed club that weighs 8 lb.

I don't care about the damage yet, but I want to know if I'm hitting you with ×16 amount of force because I'm four times as strong and my club is four times as heavy. Of course, I'm sure physics is a bit trickier than just that, but do I have the right idea? If not, I'd love to be corrected. If I'm right, wouldn't giants kill each other too easily? At ST 20, I am assumed to have four times the mass, but I'm hitting with 16 times the force. Doesn't that mean me and my other ST 20 friend pose a greater threat to each other than you and your other ST 10 friend? Is this why larger creatures (bears, elephants, etc.) seem to have higher DR on top of their higher HP?

On the other end of the spectrum, what about those two ST 5 goblins in my backyard? They are ×1/4 as strong and their knobbed clubs are ×1/4 as heavy. So, it seems they are ×1/4 the mass but hitting each other with ×1/16 the force. Is it going to take them forever to knock each other out? Does that make sense? Do small creatures (ants, squirrels, etc.) have that same issue? (It seems like some ants have Striking ST on their mandibles, which might offset that a bit.)

Spoiler:  

GURPS does seem to support this. You and your friend are doing 1d+2 crushing damage (+1 from the knobbed club) to each other with your knobbed clubs; so, it'll take ~1.82 hits to knock the other to 0 HP. Me and my friend are doing 3d+4 crushing (+2 from the knobbed club, which was sized up using LTC2) with our knobbed clubs; so it'll take ~1.38 hits to knock the other to 0 HP. With punching, it'll take you and your ST 10 friend ~6.67 hits to knock the other to 0 HP, and it'll take me and my ST 20 friend ~3.33 hits to knock the other to 0 HP.

Likewise, for the ST 5 goblins, they are doing 1d-2.5 crushing (+0.5 from the knobbed club, which was sized down using LTC2) with their knobbed clubs; so, it'll take ~5 hits to knock each other to 0 HP. I won't touch punching because the damage numbers get too weird. But that illustrates the point.

Does that make sense? Again, it's more of a thought experiment than anything else. While the GURPS numbers don't line up with my assumptions (and I didn't expect them to), they do trend in those directions, which makes me feel like I can't be far off.

Thanks.

[Anthony]

Originally Posted by Raekai

I don't care about the damage yet, but I want to know if I'm hitting you with ×16 amount of force because I'm four times as strong and my club is four times as heavy.

No. Most likely you're hitting with 4x the force.

[Ulzgoroth]

Hitting with 'force' is pretty shaky physical ground to be starting from. Calculating actual forces involved in an impact depend on body deformation physics and that's going to be pretty gross to work with.

Usually we're more likely to look at energies or cross-sectional energy densities or maybe momentum.


But personally, I'd start by looking at Basic Set p355, throwing.

By the rules there the range you get varies fairly closely with BL/weight * ST. Since BL varies with the square of ST, that means that throwing range varies with the cube of ST for a given weight. (When the weight is close enough to BL, it tails off when it's more than a factor of 4 away.)

Maximum range is proportional to the square of velocity, so when you scale up ST and weight together the implication is that throw velocity goes up proportionate to the scaling factor until the projectile gets too small. That would mean momentum goes up with the square and energy with the cube.

On the other hand, those clubs are much too small compared to BL to match that calculation. For things so light, range more or less just varies linearly with ST. So energy would go up with the square of scaling factor, and momentum with the 1.5 power of it.

[Anthony]

Originally Posted by Ulzgoroth

But personally, I'd start by looking at Basic Set p355, throwing.

The first thing you should do with the throwing rules is never look at them again.

[Ulzgoroth]

Originally Posted by Anthony

The first thing you should do with the throwing rules is never look at them again.

I don't think there's anywhere better to look for what the ST stat translates to in terms of actions faster than weight lifting.

[Rupert]

Well, the first problem is that the distance table implies that a thrower puts more energy into an object the heavier it is, yet the damage table implies that there's a point of peak efficiency, and above and below that weight ratio less energy is put into the object. Then there's the way the distance table says doubling your ST lets you throw an object four times the weight twice as far (for eight times the energy).

A start would be giving a fixed distance for a given weight ratio, not multiplying ST by the distance modifier.

If one assumes that large creatures can accelerate an object over a longer distance for more speed (like the bonus long arms give to damage), then that can be added in separately in some way.

[Anthony]

Originally Posted by Ulzgoroth

I don't think there's anywhere better to look for what the ST stat translates to in terms of actions faster than weight lifting.

The problem is that the throwing rules are nonsense.

Basically, throwing distance is equal to energy/weight * adjustment for angle, and energy is equal to force * distance (during the throwing process). This works out to (distance thrown) = (distance moved when throwing) * (force applied when throwing) / (weight) -- i.e. distance is based on arm length * BL/weight. There's some additional efficiency effects because muscle applies less force as its contraction speed increases, but in general a ST 20/SM 0 character should throw an 80 lb object (1xBL) exactly the same distance as a ST 10/SM 0 character would throw a 20 lb object. The GURPS throwing rules has the first character throw it twice as far.

[bert]

Originally Posted by Anthony

The first thing you should do with the throwing rules is never look at them again.

Would you please elaborate on why?

[Anthony]

Originally Posted by bert

Would you please elaborate on why?

I already did. 2x ST should not let you throw 4x as much 2x as far, it should let you throw 4x as much for the same distance.

[zoncxs]

If you are 4 times stronger than you will do twice the damage.

ST 10 (20) vs ST 20 (80). ST 20 is 4 times stronger, and the damage should be based on the square root of that, which means the damage should be 2 times what ST 10 can do.

with a more massive weapon, maybe a little more than that.