Introduction to Classical Mechanics · Problem 1.16
Strategies for solving problems — Morin
Physics — Mechanics · limiting_cases_drag
Problem
Projectile with drag **
Consider a projectile subject to a drag force F=−mαv. If it is fired with speed v0 at an angle θ, it can be shown that the height as a function of time is given by (just accept this here; it's one of the tasks of Exercise 3.53)
y(t)=α1(v0sinθ+αg)(1−e−αt)−αgt.
Show that this reduces to the usual projectile expression, y(t)=(v0sinθ)t−gt2/2, in the limit of small α. What exactly is meant by "small α"?