Acar approaches you at a constant speed, sounding its horn, and you hear a frequency of 76 hz. after the car goes by, you hear a frequency of 65 hz. what is the frequency of the sound emitted by the horn? the speed of sound in the air is 343 m/s.

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?

The seven sisters, seven stars located more than 400 light-years away in the taurus constellation can be seen here with venus and another constellation, orion. the seven stars stay grouped together but seem to move, like the planet venus. why do stars seem to move like planets in the night sky?

Which atomic model was proposed as a result of j. j. thomson’s work?