Hey, guys! Not really my homework question, I am long past my days of studying physics (I stumbled upon this problem doing some engineering researches) but still i put it here cause it should be rather easy. Here is the picture I made: http://img248.imageshack.us/img248/7700/riddlew.png [Broken] Basically, i've got a block of a known mass, I know friction factor and contacting area, thus I am able to calculate Friction force being exerted upon moving this block. Block is being moved by a cone. I need to know a formula for a Force needed to be applied to a cone to move the block. Thank you very much! P.S. As for my own efforts of solving, it comes down to this: I realize I have to project and equate projection of cone force to friction force but here it got a bit tricky for me. I'm very rusty in mechanics and I'm not really sure if i should project forces in this system on the side of the cone or on the surface normal of the cone side.