Hunt's Impact Theorem was developed by physicist Kieran Hunt in the latter half of 2008.

It is given by

where ? is the impact coefficient,

*m* is the mass of the impacting object,

*v* is the impact velocity,

and *d* is the depth of the crater formed.^{[1]}

The impact coefficient, ?, is 13200 ± 1720 kg·s^{-2} in dry sand.^{[2]}

It is different from Newton's impact depth formula in that Newton assumes the material is compressed through momentum (i.e. bullets) whereas Hunt uses Conservation of Energy and assumes the material is **not** compressed (i.e. a crater).

## See also

## References

**^** Hunt, K.M.R. (2008) *The nature of crater depths and volumes.***^** Hunt, K.M.R. (2008) *The nature of crater depths and volumes.*

**Source:** http://en.wikipedia.org/wiki/Hunt's_Impact_Theorem