A light beam is shining on a metal target that has a work function of 1.8 eV. If a stopping potential of 0.7 V is required, what is the wavelength of the incoming monochromatic light? (h = 6.63 × 10^?34 J?s, c = 3.00 × 10^8 m/s, 1 eV = 1.60 × 10^?19 J, and 1 nm = 10?9 m)
a. 497 nm
b. 166 nm
c. 796 nm
d. 1130 nm
e. 691 nm
a
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A. exactly 180 degrees. B. less than 180 degrees. C. more than 180 degrees.
If protons have a half-life of 1031 years, what fraction of the original protons have decayed during the 101 year existence of the universe?
a. 1/31 b. 30/31 c. 4 × 10^–7.5 d. 4/10 e. less than any of the above values
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a. 50 b. 60 c. 40 d. 70 e. 110
A wheel rotates through an angle of 320° as it slows down from 78.0 rpm to 22.8 rpm. What is the magnitude of the average angular acceleration of the wheel?
A) 2.34 r rad/s2 B) 5.48 rad/s2 C) 6.50 rad/s2 D) 8.35 rad/s2 E) 10.9 rad/s2