A nearsighted person has a far point of 33 cm. What focal length contact lens would allow her to see in the distance?
A. 33 cm
B. -33 cm
C. 67 cm
D. -67 cm
E. 3.0 m
B. -33 cm
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If the Moon is full at midnight, what will its phase be 6 hours later?
A) full moon B) first-quarter moon C) new moon D) third-quarter moon
Spherical Mirrors: Reza's face is 20 cm in front of a concave shaving mirror having a focal length of magnitude 30 cm. How large is the image of his face?
A. half as large as his face B. of the same size as his face C. twice as large as his face D. three times as large as his face E. four times as large as his face
Isaac Newton was able to estimate a value for G, the universal gravitational constant, from the following data: the radius of the Earth is about 6400 km, the average density of rocks is about 5.50 g/cm3, and g = 9.80 m/s2 near the surface of the Earth. What value did Newton obtain for G?
What will be an ideal response?
Compound Microscope: You have a choice between two lenses of focal lengths fa and fb, where fb = 2fa, to use as the objective lens in building a compound microscope. If the magnification you obtain using lens a is Ma, what will be the magnification when using lens b?
A. Mb = 2 Ma B. Mb = 4 Ma C. Mb = 8 Ma D. Mb = Ma/4 E. Mb = Ma/2