Select one correct statement: A) Specific ions are necessary for metals and alloys. B) An environment that causes SCC of one alloy would also causes SCC of another alloy. C) As specific ions form a film on the metal surface, hence, those ions which form films may be adequate to cause SCC.

An engine, weighing 3000 n, is supported on a pedestal mount. it has been observed that the engine induces vibration into the surrounding area through its pedestal at the maximum operating speed. determine the stiffness of the dynamic vibration absorber spring in (n/m) that will reduce the vibration when mounted on the pedestal. the magnitude of the exciting force is 250 n, and the amplitude of motion of the auxiliary mass is to be limited to 2 mm note: in this question type-in right numbers, no decimals, no fractions, no unit. approximate to right number if needed