# Why do fundamental physical laws involve the second derivative? [duplicate]

The title says it all. This is a question that has been nagging at me for some time. Mathematically, the first derivative is not really any different from the second derivative, or the $k$-th. So I ask, what is so special about the second derivative?

• – Brandon Enright Dec 14 '13 at 7:40
• conservation of momentum doesn't involve 2nd derivative but it is the fundamental law of nature. Farady's law states that $\mathcal{E} = -N {{d\Phi_B} \over dt}$ this doesn't involve 2nd derivative. Rather first derivative seems more inherent to nature. – user31782 Dec 14 '13 at 8:43
• Possible duplicates: physics.stackexchange.com/q/18588/2451 , physics.stackexchange.com/q/4102/2451 and links therein. – Qmechanic Dec 14 '13 at 9:41