Sir Issac Newton is one of the smartest physicist in recent history.

The reason Sir Issac Newton could not solve this problem at that time was, because ODE (Ordinary Differential Equations) wasn't available at that time.

Most of aerodynamics/aerospace equations requires ODE and some PDE (Partial Differential Equations) on a graduate level.

For 16 year old kid to solve this problem, he probably had to take 1st semester calculus at the age of 14.

I've seen some guys who took higher level of MATH at a same age, but they didn't do good on graduate level engineering courses.