Science - Simple Machines Study Notes
Six Simple Machines
1. Screw
2. Wheel and axle
3. Pulley
4. Lever
5. Wedge
6. Inclined plane
Work is defined as the movement of force through distance.
Friction is the opposing force or resistance of two surfaces rubbing together. Brakes depend on friction.
Unless friction is reduced, many machines would wear out in a very short time. Oil helps to overcome friction by providing a film between parts that rub against each other. This film fills any rough places and makes a smooth surface. Metal parts actually slide on a thin film of oil without touching each other.
Lever - a stiff bar that rests on a point called the fulcrum. The bar moves but the fulcrum doew not. The lever can help you do work by making use of force and distance.
First class – seesaw, claw hammer
Second class – bottle opener, wheelbarrow
Third class – hitting a baseball, casting a fishing rod
Inclinded Plane - plane set at an angle to the horizontal, especially a simple machine used to raise or lower a load by rolling or sliding
- is a simple machine that helps you do work without moving.
Pulleys- a pulley is a wheel wit a groove that holds a rope or cable. A load is attached to one end of the rope and when the other end is pulled, the wheel turns lifting the load. The purpose of the wheel is to reduce friction.
Block and Tackle – A combination of pulleys is called a block and tackle. It is a combination of fixed and movable pulleys that allows this simple machine to gain its greatest mechanical advantage. A three –speed bicycle.
Wheel and Axle - The wheel and axle is a simple machine made up of a small wheel attached to the center of a large wheel. The small wheel is the axle; it is usually a rod and it always turns as the large wheel turns.
Ie. Tricicyle, wrench
Wedge – a wedge is a simple machine that is used to push something apart. Most cutting tools such as knives are wedges. Naturally, the sharper a knife is, the easier it is to use because it requires less effort.
Screw- The screw can be thought of as a twisted wedge.
Robertson screw driver
Phillips screw +
Slot –
Torx *
