# Longbow arrow safety curtain

1. Aug 17, 2011

### jack616

My longbow arrow problem has moved on from materials and I'm now trying to
understand how to calculate projectile vectors.

If anyone can help I'd appreciate it - I havn't done much math for 25 years so
I'm essentially having to re-learn.

Problem:

A longbow arrow weighing around 100grn (6.5gms) is falling toward a target
In front of the target is a thin protective curtain.
I don't need the curtain to stop the arrow - just deflect it so it falls short of the target
...and doesnt kill the audience. (Bad form I'm told...)

Assume for now that the arrow cannot penetrate the curtain. If it helps the curtain
could be installed at any angle. It must however be light and flimsy it cannot be brick etc.

Is there a formula I can use to calculate the vectors and hopefully go on to calculate
the energies needed to deflect it through a set angle. I can do the energy of the arrow (1/2 MV2) but I dont know
how the vector math is applied for this problem - or what the formula might be - if that makes sense.

Any useful formulas for deflection and vector calculation would be welcome.
I think I'm approaching the problem the right way?

Thanks
jack