Torque is probably my favorite physics concept because it's so simple and appears in all kinds of places.  Torque is a measure of force times distance.  You can generate more torque by applying the same force at a greater distance from a rotation point.  It's the reason why wrenches tighten things better than screw drivers.  It's the reason why those little Allen keys are double-sided -- one side is for quickly screwing something in; the other side is for tightening.  It's the reason you do bicep curls by holding a dumbbell in your hand and not on your forearm.  It's the reason why, when my ax gets stuck in a piece of wood, I grip it as far away from the ax head as possible to get it unstuck.  It's the reason why branch-cutting shears have really long handles.  It's the reason why lug nut wrenches are sometimes double-sided (double the torque) or have really long handles. 

When in doubt, use a longer lever. #science