Horse and Lance Momentum and Energy

[Adam]

How much force do you think a charging horseman would deliver with a lance?

Given that a canter speed is approximately 4m/s...

 

[HallsofIvy]

You would also have to know the mass of the horse-man combination so that you could calculate the kinetic energy. Now you will have to estimate the time that would be required to come to a full stop if they were to charge into a solid wall! Knowing the time required to stop gives you the acceleration and then F= ma.

That gives the maximum possible force. Of course, the force that can be applied is likely to be the smaller of that and the force necessary to shatter the lance!

 

[Adam]

Horse maybe 500 kg.
Man around 90 kg.
Armour example maybe 15 to 25 kg.
Lance 4 or 5 kg.

Target would be a human, say 90kg again, plus armour another 15 to 25 kg.

I'm not sure how to factor in the elasicity of the bodies and the couching arm, nor the fact that the target body will move as it is struck.

 

[LURCH]

Actually, I don't think those numbers are really needed. If I understand correctly, the lands was held in one hand and brace against the rider's body. So the real force of impact one could generate with a lance was dependent upon how much "back pressure" one's arm and torso could withstand.

 

[NateTG]

Don't ask about force, ask about linear momentum and energy:

the horse and rider has a momentum of
600 kg x 4 ms => 2400 kgm/s
and KE of
1/2 * 600 kg x 4 ²=> 4800J

Now we have 100 kg of opponent and we're looking at a totally ineleastic colision, that's going to dissapate about 600 J of energy.

This is comparable to the energy that's in a bullet, but much more momentum.