A contact lens is made of plastic with an index of refraction of 1.50 . The lens has an outer radius of curvature of +2.0 cm and an inner radius of curvature of +2.5 cm. What are the focal length and the power of the lens?
+20 cm, +5.0 diopters
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If a reaction is exothermic and produces large quantities of heat reaching equilibrium, its equilibrium constant will be
A) negative, because it is an exothermic reaction. B) zero, because the reaction will not have an equilibrium constant. C) small (less than. D) large.
A CD with a diameter of 12.0 cm starts from rest and with a constant angular acceleration of 1.00 rad/sec2 acquires an angular velocity of 5.00 rad/sec. The CD continues rotating at 5.00 rad/sec for 15.0 seconds and then slows to a stop in 12.0 second with a constant angular deceleration. What is the angular distance traveled by a point 4.00 cm from the center, at the time 10.0 seconds from the start?
A. 27.6 rad B. 37.5 rad C. 40.7 rad D. 48.2 rad E. 51.2 rad
Some recent evidence points to the possibility of there being some liquid water on Mars "recently." Why does this puzzle astronomers?
A. Currently Mars is too hot for liquid water. B. The Martian atmosphere is too cold and has too low a pressure for liquid water. C. The Martian atmosphere is too thick, and clouds would form. D. All of these choices are correct.
An ant and an elephant are walking through the jungle. On which does the greater buoyant force act?
A. The elephant B. The ant C. The same buoyant force acts on both D. Neither is floating, so no buoyant force is acting at all