The main difference between speed and velocity involves
a. gravity.
b. distance.
c. weight.
d. direction.

Ais useful when you need a simple machine to you separate two things. a. lever b. screw c. pulley d. wedge

How is sound energy produced a. vibrating objects b. objects being heated c. temperature differences d. stationary objects

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.