DAY 8 - BALDERDASH!

Manning's equation (man′·niŋz ē kwā′z̸hən)
noun, etymology: (Old Norse) Menning- able; (Latin) æquatio- an equalizing, equal distribution.

1.  The secret ingredient in Dos XX--it is the most interesting equation in the world.

2.  F = ma.

3.  An empirical equation that applies to uniform flow in open channels and is a function of the channel velocity, flow area, and channel slope.

4.  The basis behind Men Are From Mars, Women Are From Venus.

And the answer is.....?