Across
- 4. quantity with direction (e.g. velocity)
- 5. quantity with no direction (e.g. distance)
- 8. magnitude in years of age of the universe
- 9. force of gravity on a mass
- 11. theory of the beginning of the universe
- 13. closest star to Earth
- 15. longest wavelength electromagnetic radiation
- 17. rate of change of speed
- 18. type of background radiation that provides evidence for the Big Bang
- 19. the lightest element in the universe
- 20. change in sound as frequency of sound wave changes
Down
- 1. push or pull
- 2. part of the electromagnetic spectrum used for cancer treatment
- 3. change in sound as amplitude of sound wave changes
- 6. type of wave where particles oscillate parallel to wave direction
- 7. distance light travels in one year
- 10. resistance to change in motion
- 12. net force is zero
- 14. unit for force
- 16. increase in light wavelength from sources moving away