1. The problem statement, all variables and given/known data A bullet of mass m strikes an amor plate with initial velocity v0. As the bullet burrows into the plate, its motion is impeded by a frictional force which is directly proportional to the bullet's velocity. There are no other forces acting on the bullet. -Use Newton's Second Law to set up an IVP for the position of the bullet -How thick should the plate be to stop the bullet? 2. Relevant equations [None given with problem] 3. The attempt at a solution I attempted to use a modified version of a harmonic oscillator formula, where there is no spring. Only the momentum of the object and the friction force resisting it. m*d^2x/dt^2-kdx/dt=0. However, in solving it I've run into a problem. While I got an equation for x, x(t)=v0*e^Rt/(R-1)-v0/(R-1) (where R=m/k), trying to use that to find the time at which the bullet stops yields 0=v0*R*e^Rt/(R-1) e^x=/=0, regardless of x, so there is no possible time at which dx/dt=0. Is my model flawed, or have I made some other error?