Radioisotopes are used in a variety of manufacturing and testing techniques. Wear measurements can be made using the following method. An automobile engine is produced using piston rings with a total mass of 100 g, which includes 9.4 mCi of ºFe whose half-life is 45 days. The engine is test-run for 1500 hours, after which the oil is drained and its activity is measured. If the activity of the engine oil is 3.72 x 103 decays/s. (a) How much mass was worn from the piston rings per hour of operation? (b) What would be the activity in the piston after 0.0802 grams has been worn off the piston?

Radioisotopes are used in a variety of manufacturing and testing techniques. Wear measurements can be made using the following method. An automobile engine is produced using piston rings with a total mass of 100 g, which includes 9.4 mCi of ºFe whose half-life is 45 days. The engine is test-run for 1500 hours, after which the oil is drained and its activity is measured. If the activity of the engine oil is 3.72 x 103 decays/s. (a) How much mass was worn from the piston rings per hour of operation? (b) What would be the activity in the piston after 0.0802 grams has been worn off the piston?