D. Inclined Plane  Inclined Plane sloping surface used to raise objects h l

E. Screw  Screw inclined plane wrapped in a spiral around a cylinder

F. Wedge  Wedge a moving inclined plane with 1 or 2 sloping sides

F. Wedge  Zipper 2 lower wedges push teeth together 1 upper wedge pushes teeth apart

Problems  How much force must be exerted to push a 450 N box up a ramp that is 3 m long and 1.2 m high? GIVEN: F e = ? F r = 450 N l = 3 m h = 1.2 m WORK : IMA = l ÷ h IMA = (3 m)÷(1.2 m) IMA = 2.5 IMA l h MA FrFr FeFe F e = F r ÷ MA F e = (450 N)÷(2.5) F e = 180 N