A spring is stretched from x=0x=0 to x=dx=d, where x=0x=0 is the equilibrium position of the spring. It is then compressed from x=0x=0 to x=−dx=−d. What can be said about the energy required to stretch or compress the spring?

Choose a synonym for the underlined homonym (a word with two or more meanings). i did not expect the boat to rock so much. a. boulder c. astound b. sway d. shock

Carbon is allowed to diffuse through a steel plate 15 mm thick. the concentrations of carbon at the two faces are 0.65 and 0.30 kg c/m^3 fe, which are maintained constant. if the preexponential and activation energy are 6.2 x 10-7 m2 /s and 80,000 j/mol, respectively, compute the temperature at which the diffusion flux is 1.43 x 10^-9 kg/m^2 -s.

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.