Simple Machines

• There are 6 types of simple machines: the inclined plane, the wedge, the screw, the lever, the pulley, and the wheel and axle.

Simple Machines

• A ramp is an example of an inclined plane.

• A ramp decreases the amount of force you need to exert, but it increases the distance you must exert force.

inclined plane

Simple Machines

• A wedge is an inclined plane that moves.

• A wedge is usually a piece of wood or metal that is thinner on one end than the other.

Simple Machine

• The screw is an inclined plane wrapped around a central bar, or cylinder, to form a spiral.

• The mechanical advantage of a screw increases when the threads are closer together.

Simple Machine

• A lever is a rigid bar that is free to pivot, or move about, a fixed point.

• The fixed point is called a fulcrum.

• When a force is applied on a part of bar (lever) by pushing or pulling it, the lever swings about the -

fulcrum and overcomes the resistance force.

Simple Machine

• A pulley is a rope, belt, or a chain wrapped around a grooved wheel.

• A pulley can function in 2 ways:

• It can change the direction of a force or the amount of force.

Simple Machines

• A wheel and axle is a simple machine made up of two circular objects of different sizes.

• The wheel always moves through a greater distance than the axle.

Simple Machine

• The mechanical advantage of a wheel and axle depends on the radius of the wheel and of the axle.

• If the radius of the wheel is 4x greater than the radius of the axle, every time you turn the wheel once, -

your force is multiplied by 4.

Simple Machine

• A compound machine is a combination of two or more simple machines.