Across
- 2. when we resolve forces, we break them into a horizontal and a vertical .....
- 5. type of deformation where an object does not return to original shape when forces removed.
- 8. this is the speed AND the direction the object is moving in
- 13. alpha radiation is the most ....
- 14. time taken for the activity of a radioactive source to become 50% its initial value
- 15. 3 m/s is the typical average speed of someone ...
- 16. type of radiation that is the most ionising.
- 17. the collective word for protons, neutrons and electrons
- 18. the overall force. e.g. if one force is 5N left and other force is 3N right, this answer would be 2N left.
- 19. a quantity with magnitude and direction. e.g force, acceleration.
- 20. we draw this line, which touches the curve at one point, to find the instantaneous speed.
- 23. gamma radiation is the most ....
- 24. this scientist has a law named after him that says; for some materials force is proportional to extension
Down
- 1. something that cause objects to start moving, stop moving, change shape etc
- 3. how far away object is from where it started. has direction. units are metres
- 4. the number of detections of radiation per second is called the ..... -rate
- 6. the number of nuclei in a sample decaying per second. Measured in Becquerels
- 7. this force acts straight down (or towards centre of planet) and is different on different planets
- 9. when radiation from a source strikes an object or person
- 10. when radioactive substances get in or an an object
- 11. the unit we use for forces
- 12. the force pushing up at 90 degrees from a solid surface is called the .... contact force
- 21. the process of a radioactive nucleus changing and giving off radiation
- 22. the fact that we don't know exactly when a nucleus will decay