I'm not sure if this is the appropriate subforum, but here it goes: Suppose you have a particle, with the mass m, at the bottom of jar which is filled with liquid. The particle is shot upwards, parallel to the gravitational force, with the speed v0. The drag force is proportional to the particle's speed. What is the maximum height ymax of the particle? First, "down"force equals to: Ft=W+Fd m*a=m*g+b*v => a(v)=g+(b/m)v v(t)=v0+a*t, at ymax: v(t)=0 => 0=v0+a*t ... With cross subtituting, I cannot eliminate the variables v or t from the ymax function. Somehow I think the ymax function should not depend on the v or t variables, but maybe I'm wrong. Can you guys help me? Thanks!