"Mathematics In Action" by O.G. Sutton

This book has number of essays on the profession of Mathematician, tools
a Mathematician uses and interesting examples. Some of the chapters
include applications in Ballistics, Waves, flight, meteorology and
statistics. The math is about the 2nd term calculus level and is not too
opaque.

I've enjoyed reading this book; this is the kind of book
that anyone interested in math and physics should find irresistible!