/sci/ - Science & Math

Quick sanity check.
Ignoring [math]f[/math], the resultant force on the block is [math]mg \sin \theta[/math], right? [math]mg \cos \theta[/math] and [math]N[/math] cancel out.
The real issue is, basically, that if a penny is spinning frictionlessly in a cone, then the resultant force needs to point to the cone's vertex, so it eventually falls in, right?