Vocabulary terms to know:

1. Force: Think of a push or pull. It can make things move, change direction, or deform.

2. Friction: The rubbing of one thing against another. It creates resistance to movement and can make things slow down or stop.

3. Pressure: Force acting on a specific area. Think of the pressure of your foot on the ground or the pressure of water in a pipe. 

4. Simple Machines: These are tools that make work easier. Examples include levers (like a seesaw), pulleys (like a rope system), inclined planes (a ramp), wheels and axles (like a bike), wedges (like an axe), and screws (like a bolt).

5. Gears: Wheels with teeth that mesh together to transfer motion. They can change speed and direction.

6. Power: The rate at which work is done or energy is transferred. It's often measured in watts.

7. Energy: The ability to do work. It comes in different forms, like kinetic (motion), potential (stored), and thermal (heat).

8. Motion: Movement or change in position.

9. Design: The process of creating something new, whether it's a machine, a bridge, or a building.

10. Engineering: The use of scientific knowledge and creativity to design and build things that solve problems.