A far-sighted student has a near point of 1.0 m. Calculate the focal length (in cm) of the glasses needed so the near point will be normal (25 cm).
A. 72
B. 25
C. 33
D. 100
E. ?33
Answer: C
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In the above model of an atom, if you were to draw an electron’s transition from the second excited state to the third excited state, what numbers would this correspond from/to? What kind of spectrum would be produced?
a. 3 to 4, absorption
b. 2 to 3, absorption
c. 3 to 4, emission
d. 2 to 3, emission
Stellar masses are measured directly by observations of the motions of
A) spectroscopic binary systems. B) visual binary systems. C) eclipsing binary systems. D) All of the above can give us their masses. E) Stellar masses cannot be measured directly by any method.
A certain pendulum consists of a 1.5-kg mass swinging at the end of a string (length = 2.0 m). At the lowest point in the swing the tension in the string is equal to 20 N. To what maximum height above this lowest point will the mass rise during its oscillation?
a. 77 cm b. 50 cm c. 63 cm d. 36 cm e. 95 cm
You are building a compound microscope with an objective lens of focal length 1.1 cm and an eyepiece lens of focal length 5.0 cm. You mount the lenses 18 cm apart. What is the approximate magnification of your microscope?
a. 3 c. 80 b. 7 d. 130