Rodent Wars Forum

Sometimes an attack sends someone flying or knocks them down. One can determine the energy or force of the attack with simple physics.

By flying speed
In this method, we can determine the force of the attack, in Newtons. The formula is...
     F=m*γ where F is the force, m is the mass of the object being thrown (in kg), * means "multiply", and γ is the acceleration of the object.
     For example, here is a calculation from the Weapon/kick/fist impact calculations thread.
     
m = about 0.05 kg (50g) for a RW Dwarf with armor.
γ = 0.127 m/s ÷ 1 sec = 0.127 m/s

F=m*γ
0.05 x 0.127 = 0.00635 Newtons (N)

That's about 0.6475 grams. This may sound easy—a mouse can lift up to about 100 grams—but it fails to take into account that the Dwarves are moving through the air very slowly, unrealistically so. In real life, that much force would just move them a little. All calculations done with this method should be approached very cautiously, as flying speed and distance traveled rarely match up in fiction, so we prefer to just go with the distance.


Distance thrown
This method is used by VS Battles Wiki, and is more exact and reliable than the other, but it is harder to use. I have simplified it, but I don't know for sure if I got it right, or even if it's trustworthy, though we get similar results as with the other methods most of the time. Use kg for mass, m/s for velocity, m for height and distance, and J for energy.

First, find potential energy, or PE:
mass x acceleration of gravity x distance fallen or thrown = PE

PE to velocity:
PE = 0.5 x m x velocity˛
I'll put a random number in (0.0225) to help.
0.5 x PE = y
PE ÷ y = velocity

0.5 x mass x (velocity)˛ = KE (kinetic energy) of the attack. This is the attack strength.

Here's an example:

h = 0.1143 cm
d = 0.05715 cm
m = 0.045 kg

First, find potential energy, or PE:
mass (0.045) x acceleration of gravity (9.8˛) x distance fallen (0.05715) = 0.24699087 joules (I’ll round to 0.25)

PE to velocity:
PE = 0.5 x m x velocity˛
0.25 = 0.5 x 0.045 x velocity˛
0.5 x 0.045 = 0.0225. We know that the PE divided by 0.0225 will equal velocity, so:
0.25 ÷ 0.0225 = 11.1111111111 (I’ll round to 11)
Velocity = 11 m/s

Kinetic energy (KE) of the attack =  0.5 x mass x (velocity)˛
0.5 x 0.045 x 11 = 0.2475
0.2475 x 0.2475 = 0.06125625 joules.

The energy of the attack is 0.06125625 J. Let’s round that to 0.06 J.

I'm not knowledgable enough to tell you whether this is a very accurate method, but it does generally match up with methods for destruction.