Question 1
A beam of 1-MeV gamma rays incident on a piece of 0.50-cm thick lead is reduced by 50% of its initial value. How thick must the lead be to reduce the beam to one percent of its initial value?
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1.1 cm
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2.2 cm
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3.3 cm
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4.4 cm
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8.4 cm
Question 2
A neutron is characterized by the term "thermal neutron" when
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its energy is of the order kT, where T is on the order of 0°C.
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its energy is of the order kT, where T is on the order of 0 K.
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its energy is of the order kT, where T is on the order of 273°C.
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its energy is of the order kT, where T is on the order of 100°C.
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its energy is of the order kT, where T is on the order of 0°R.