In a harry potter movie, there is a big pendulum in the great hall that goes back and forth once every 18.9 s. what is the length of the pendulum(if it obeys physics instead of magic)? (unit=m) PLEAS HEL M

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.