Which of the following situations would cause the greatest decrease in the motion of molecules in a system?
a. q = -50 j, w = -50 j
b. q = +50 j, w = +50 j
c. q = -50 j, w = +50 j
d. q = +50 j, w = -50 j

Henry, whose mass is 95 kg, stands on a bathroom scale in an elevator. the scale reads 830 n for the first 2.4 s after the elevator starts moving, then 930 n for the next 2.4 s. part a what is the elevator's speed 4.8 s after starting? express your answer with the appropriate units.

What accounts for an increase in the temperature of a gas that is kept at constant volume? a. energy has been removed as heat from the gas. b. energy has been added as heat to the gas. c. energy has been removed as work done by the gas. d. energy has been added as work done by the gas.

The first law of thermodynamics states that heat added to a system is neither created nor destroyed but is as it changes into other forms of energy.