2. If a spring has a spring constant of 400 N/m, how much elastic potential energy is stored when the spring is stretched by 0.25 m?

12 drag each label to the correct category. decide whether each statement describes mass or weight. measured in newtons measured in kilograms does not change when gravity changes === a gravitational force changes when gravity changes the amount of matter in something mass weight

To create electromagnetic induction, which of the following has to move? a. a wire b. a magnet c. a transformer d. either a or b

15. give an example for some particles or waves that are moving faster than light in everyday life 16. what is a laser? 17. what is an oscilloscope? 18. what does it means practically that nothing is faster than light in vacuum? 19. what is vacuum?