1. as described by the first law of thermodynamics, the change in internal energy of a system is equal to a. the sum of the heat added and work performed b. the difference between the heat added and work performed c. the product of the pressure and change in volume d. the ratio of the heat added to the work performed 2. a 3.1-mole sample of an ideal gas is gently heated at constant temperature 290 k. the gas expands to 1.5 times its initial volume as its pressure decreases. what is the change in the internal energy of the gas? let the ideal-gas constant r = 8.314 j/(mol • k). a. 0 j b. 1500 j c. 3000 j d. -3000 j just give the answer no long answers

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.