What was needed to develop in Earth's atmosphere to protect organisms from the harmful effects of ultraviolet radiation?
a. weather patterns
b. a nitrogenous layer
c. a greenhouse effect
d. an ozone layer
e. reflective clouds
d
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How long is the precession cycle?
A) 1 day B) 29.5 days C) 365.24 days D) 18 years, 11.3 days E) 26,000 years
An object is moving with constant non-zero velocity in the +x direction. The velocity versus time graph of this object is
A) a horizontal straight line. B) a vertical straight line. C) a straight line making an angle with the time axis. D) a parabolic curve.
A series LC circuit contains a 100 mH inductor, a 36.0 mF capacitor and a 12 V battery. The angular frequency of the electromagnetic oscillations in the circuit is
a. 36.0 × 10^?4 rad/s. b. 6.00 × 10^?2 rad/s. c. 2.78 rad/s. d. 16.7 rad/s. e. 277 rad/s.
Classical theory predicts that the planets can orbit the Sun quite stably
Why could not stable orbits be predicted for the atom by simply substituting the electrical attraction for the gravitational attraction? Why was there a classical crisis in describing the atom?