Afreight train car with a mass of 1.2 _ 104 kilograms, travelling with a velocity of 23 meters/second, collides with a stationary freight train car of equal mass. what is the momentum of the system after the collision?
a. 1.2 × 105 kilogram meters/second
b. 1.4 × 105 kilogram meters/second
c. 2.4 × 104 kilogram meters/second
d. 2.8 × 105 kilogram meters/second

Abag of potato chips contains 2.00 l of air when it is sealed at sea level at a pressure of 1.00 atm and a temperature of 20.0 deg c. what will be the volume of the air in the bag if you take it with you, still sealed, to the mountains where the temperature is 7.00 deg c and atmospheric pressure is 70.0 kpa? assume that the bag behaves like a balloon and that the air in the bag is in thermal equilibrium with the outside air.