Prove that each of the following languages is decidable by constructing a turing machine that decides it and showing that this construction is correct. hint: you may use any of the turing machines constructed in class as a subroutine of your turing machine. a. = {⟨ ⟩ |⊆ }

5g of ammonium nitrate was dissolved in 60g of water in an insulated container. the temperature at the start of the reaction was 23.0°c and at the end it was 19.0°c. calculate the energy absorbed by the reaction.

Because air contracts as it cools, the air pressure inside a freezer is typically lower than on the outside. why do ice cubes inside a freezer tend to shrink over time? a. the ice dissolves oxygen from the air, forming a denser crystalline matrix. b. the ice reacts chemically with carbon dioxide in the air, forming gaseous carbon compounds. c. the ice melts, and then the liquid freezes as ice crystals on the bottom of the freezer. d. the ice sublimes, and then the water vapor deposits as ice crystals on the sides of the freezer.

Why is the energy that results from a roller coaster's position at the top of a hill referred to as potential energy?