Across
- 1. / The force that pulls objects toward Earth (7)
- 3. / Material used to make wires (6)
- 7. / Machines that help lift or move heavy objects (6)
- 11. / Tool used to drive nails (6)
- 12. / Material that conducts electricity (5)
- 15. / Fastening device, often metal, used to hold pieces together (4)
- 17. / Shape with three sides (8)
- 18. / Instrument for measuring length (5)
- 20. / Device that converts energy into motion (5)
Down
- 2. / Device used to measure temperature (11)
- 4. / Liquid used for cutting or lubricating machines (3)
- 5. / Machine part that rotates to transmit motion (5)
- 6. / Safety item worn on the head (6)
- 8. / Type of bridge that has cables (5)
- 9. / A gas used to inflate balloons or used in welding (5)
- 10. / A drawing that shows the design of something (10)
- 13. / A structure that spans gaps, e.g., over rivers (6)
- 14. / Type of energy stored in moving objects (7)
- 16. / Energy that comes from the Sun (5)
- 19. / Protective clothing for eyes (7)