# Magnets & Simple Machines

## 22 terms

### Magnets

uses property of magnetism

### Magnetic field

the lines of force surrounding a permanent magnet or a moving charged particle

### Magnetic force

the attraction or repulsion between magnetic poles

### Law of Magnetism

Law stating that opposite magnetic poles attract and like magnetic poles repel.

### Magnetosphere

the magnetic field of a planet

### Magnetic domain

Groups of atoms with aligned magnetic poles

### Ferromagnetic material

a material that shows strong magnetic properties

### Simple machine

a device for overcoming resistance at one point by applying force at some other point

### Lever

a rigid bar pivoted about a fulcrum

### First-class lever

The fulcrum is positioned between the effort and resistance

### Second-class lever

The fulcrum is positioned at one end of the bar and the resistance is between the fulcrum and the effort

### Third-class lever

The fulcrum is at one end of the bar and the effort is between the fulcrum and the resistance

### Fulcrum

the pivot about which a lever turns

### Input arm

the distance between the input force and the fulcrum

### Output arm

the distance between the output force and the fulcrum

### Wheel and axle

simple machine that consists of a shaft or axle attached to the center of a larger wheel, so that the shaft and the wheel rotate together

### Inclined plane

a simple machine for elevating objects

### Wedge

something solid that is usable as an inclined plane (shaped like a V) that can be pushed between two things to separate them

### Screw

a simple machine of the inclined-plane type consisting of a spirally threaded cylindrical rod that engages with a similarly threaded hole

### Pulley

a simple machine consisting of a wheel with a groove in which a rope can run to change the direction or point of application of a force applied to the rope

### Gears

wheelwork consisting of a connected set of rotating gears by which force is transmitted or motion or torque is changed

### Compound machine

a machine made of more than one simple machine