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The power obtained in a reactor using 235U disintegration is 1000 kW. The mass decay of 235U per hour is
(3) 40 microgram
Energy produced in one hour:
E = Pt = 106 W 3600 s = 3.6 109 J
By mass–energy equivalence, E = m c2:
m = Ec2 = 3.6 109(3 108)2
= 4 10-8 kg = 40 10-9 kg
m = 40 microgram
Answer: (3)
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