Optics of the Eye: The closest object that a typical young person with normal vision can focus on clearly is closest to
A. 1 cm.
B. 10 cm.
C. 25 cm.
D. 50 cm.
E. 75 cm.
Answer: C
You might also like to view...
A white dwarf star is prevented from collapsing by
a. nuclear energy it is generating. b. its gravitational force. c. Hubble's law of extragalactic redshifts. d. degenerate electron gas pressure. e. degenerate astronomers observing the star.
Moment of Inertia: Two uniform solid spheres have the same mass, but one has twice the radius of the other. The ratio of the larger sphere's moment of inertia about a central axis to that of the smaller sphere is
A. 4/5. B. 8/5. C. 1/2. D. 2. E. 4.
When an atom undergoes a "quantum jump" into a lower-energy state, the atom
A) emits a photon. B) absorbs an electron. C) absorbs a photon. D) emits an electron. E) None of the above.
Two equal-magnitude forces are exerted to a door at the doorknob. The first force is exerted perpendicular to the door, and the second force is exerted at 30° to the plane of the door. Which force exerts the greater torque about the door hinge?
A) the first force (exerted perpendicular to the door) B) the second force (exerted at an angle) C) Both forces exert equal non-zero torques. D) Both forces exert zero torque.