Radioactive Decay: A hospital patient has been given a sample of 131I , which has a half-life of 8.04 days. This sample is decaying at 5.9 times the acceptable level for exposure to the general public. How long must the patient wait for the decay rate of the sample to reach the acceptable level?

A. 21 days
B. 14 days
C. 9.9 days
D. 8.9 days


Answer: A

Physics & Space Science

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If the Moon is suddenly and inexplicably moved to four times its current distance from Earth, its orbital speed ________.

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For an ideal inductor in an ac circuit, how much energy is stored in the inductor at the instant when the current is zero?

A. maximum B. 1?2 maximum C. 0.707 maximum D. zero

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If a hydrogen atom absorbs a photon of the correct wavelength, its electron will move ________ the nucleus.

A. into B. away from C. around D. toward

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An elastomeric bearing pad is subjected to a shear force V during a static loading test. The pad has dimensions a 5 150 mm and b 5 225 mm, and thickness t 5 55 mm. The lateral displacement of the top plate with respect to the bottom plate is 14 mm under a load P 5 16 kN. The shear modulus of elasticity G of the elastomer is approximately:


(A) 1.0 MPa
(B) 1.5 MPa
(C) 1.7 MPa
(D) 1.9 MPa

Physics & Space Science