Anickel engine part is coated with sic to provide corrosion resistance at high temperatures. if no residual stresses are present in the part at 20°c, determine the thermal stresses that develop when the part is heated to 1000°c during use. the elastic modulus of sic is 60 × 106 psi. the coefficient of thermal expansion for sic is 4.0 x 10-6 / °c. if the sic goes past a tensile strength 25,000 psi, the coating will crack. does the thermal stress go over 25,000 psi?

Cells in the nervous system have a potential difference of 70 mv across the cell membrane separating the interior of the cell from the extracellular fluid. this potential difference is maintained by ion pumps that move charged ions across the membrane. is this an emf? select the correct answer and explanation. 1)no. the ion pumps cannot separate charges; thus, they cannot create a potential difference. 2)yes. the ion pumps cannot separate charges, but they still can create a potential difference. 3)yes. the ion pumps can actively separate charge; thus, they can create a potential difference. 4)no. the ion pumps can separate charges, but they cannot create a potential difference.