f = ma
f = force
m = mass
a = acceleration
These three laws along with gravity form the cornerstone of modern physics. Not much outside quantum mechanics makes since with out them. They affect every aspect of our lives and are involved in some way with every thing we do.
The three laws are most evident in space flight. The 3rd law provides force to move a rocket, the 2nd law turns that force into acceleration and the 1st law keeps a space craft in obit or moving through deep space.