Achemical reaction takes place in a container of cross-sectional area 50 cm2. as a result of the reaction, a piston is pushed out through 15 cm against an external pressure of 121 kpa. calculate the work done by the system. (3 sig figs, answer in j) before starting the calculation, be sure to ask yourself whether or not this is a reversible process. question 1 options:

Which expression allows you to determine the mechanical advantage of an inclined plane? a. height of plane / input force b. length of plane / input force c. length of plane / height of plane d. height of plane / length of plane

Which is not an example of how an object gains elastic potential energy by stretching? a. jumping on a pogo stick b. pulling on a rubber band c. jumping on a trampoline

Why is rain likely when warm, moisture-laden air meets cold air? a) the lighter warm air will rise and cool down, causing condensation and rain. b) the cold air moves faster and pushes the warm air away, causing condensation and rain. c) the moisture in the warm air condenses on contact with the cold air, causing rain to fall. d) the cold air mixes with the warm air, reducing its temperature causing moisture to condense.