If you were creating a presentation that would cover the different types of muscles in the body, which groups of muscle would you need to include?

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.

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.

What kind of simple machine is a catapult?