In the real world, there would be friction between the wheels and the tracks. How does this friction affect the energy of the roller coaster system?

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?

Suppose that the half-life of an element is 1000 years. how many half-lives will it take before one-eighth of the original sample remains? 8 125 12.5 3

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.