The cosmic background radiation is A)
the flux of visible radiation in empty space, contributed by all visible stars in the universe.
B)
the radio noise generated by Earth-bound transmitters, spreading out into space since about 1920.
C)
the beam of atomic nuclei known as cosmic rays that continuously rain down upon the Earth from all directions in space.
D)
low-intensity radio noise, with a 3 K blackbody temperature, almost uniform in intensity in all directions.

Which of these are physical changes in matter? check all that apply. boiling water a pencil being sharpened exploding dynamite freezing water rotting cheese

Momentum lab this lab uses a phet simulation. navigate to the phet momentum simulation. if you don’t see the image below when you click on the link, then you need to either enable adobe flash (click on the puzzle piece on your screen) or you need to install adobe flash (this is a free program). change the vectors to be momentum vectors only. they are yellow. make the mass of both balls the same. hit play and notice what happens to the momentum vectors before and after the collision. you might want to play the sim multiple times. click on restart or return balls to start over. to see numbers, check the show values box (inside the green box). red’s momentum vector before the collision is green’s momentum vector after the collision. question 1 options: shorter than longer than equal to question 2 (1 point) saved since green bounces off red, this must be an collision. question 2 options: explosion inelastic elastic question 3 (1 point) red transfers of its momentum to green during the collision. question 3 options: little all most none question 4 (4 points) why does red transfer all its momentum to green? back up your answer with information from the simulation. write at least 2 sentences.

Pls ! what are 3 examples of acceleration that doesn’t involve a change in speed ?