1. The problem statement, all variables and given/known data A projectile of mass m is fired from ground level with speed v0 and at angle ##\theta## with respect to the horizontal. Basically there is a projectile from start to finish, with an pivot starting at the x coordinate for the highest point on the projectile. The teacher wants us to find the net torque vector, angular velocity vector, moment of inertia, and angular momentum vectors. 2. Relevant equations 3. The attempt at a solution I have trouble understanding how projectile motions can even be looked at like a rotational system. To me, the only force ever acting is gravity, but then the projectile is rotating around the origin, so shouldn't that mean that there's also another torque force? If the only force is g, then the torque would be mgr (r is the distance from the pivot) at the start point and then 0 at the top (since the g force is towards the pivot so no force done)? Also why does the teacher emphasize looking for the torque VECTOR? Does that mean that it's point towards us?