The yield strength for an alloy that has an average grain diameter of 5.4 × 10-2 mm is 123 MPa. At a grain diameter of 8.9 × 10-3 mm, the yield strength increases to 232 MPa. At what grain diameter, in mm, will the yield strength be 247 MPa?

An electric kettle is made out of stainless steel, weighs two pounds (when empty) and is equipped with a heating element that consumes 2 kw of electricity. assuming that the water and the kettle are at the same uniform temperature at any moment of time, calculate the shortest possible time to bring 2 quarts of water from room temperature to the onset of boiling