Across
- 3. What can we observe when plannets maving away from us
- 7. Our Sun lies on the _____ of the Hertzsprung-Russell Diagram
- 10. The derivative of velocity
- 11. Scientist who stated that "Every point on a wave-front may be considered a source of secondary spherical wavelets"
- 12. The base unit of electric current
Down
- 1. The place in space where even light cannot escape
- 2. Number of complete cycles per second
- 4. The science of origin, evalution of the universe
- 5. Force of attraction that holds people to stay on the Earth
- 6. The synonym of this word can be electric potential difference
- 8. Wave that was made by two progressive waves with the same frequency, amplitude travelling in opposite directions
- 9. The flow of the electric chage