Science Unit 2: Forces, Machines, and Work (Pages B31-B51)

Vocabulary words

Pages B 31-B 41

1. Force: a push or a pull on an object.

2. Friction:  a force that makes moving objects slow down or stop.

3. Gravity: a force that pulls objects toward the center of the earth.

4. Magnetism: the force that magnets produce. Metal objects made of iron are magnetic.

5. Poles: the ends of the magnet.

6. Repel: to push away. Like poles repel each other. The north pole of a magnet will repel the north pole of another magnet.

7. Attract: to come together. Unlike poles attract each other.  The north pole of one magnet will attract the south pole of another magnet.

Pages B44-B51

1. Work: is done when a force makes an object move. Work is done when an object moves in the same direction it is pushed or pulled.

2. Simple Machine: A tool that has few or no moving parts. They make work easier.

3. Lever: a simple machine made of a bar or board.

4. Fulcrum: The point where the lever rests. Think of a sea saw. The fulcrum is the place near the middle where the the sea saw board rests.

5. Inclined Plane: is a simple machine with a slanted flat surface. (Ramp)

6. Screw: is an inclined plane wrapped around a rod. Used to hole things together.

7.Wedge:made of 2 inclined planes that come together. Think a wedge of cheese shape.  Used to split wood.

8. Wheel and axle: made of a rod or bar and attached to the center of a wheel. (Think roller skate or car wheels)

9. Gears:   wheels with jagged edges like teeth. (Found inside the Judy Clocks)