The near point of a farsighted person is 100 cm. She places reading glasses very close to her eyes, and with them she can comfortably read a book at a distance of 25 cm. What is the power of the lenses in her reading glasses?
A) +2.5 diopters
B) +3.0 diopters
C) +3.2 diopters
D) -2.0 diopters
B
You might also like to view...
Compound Microscope: Which one of the following is a characteristic of a compound microscope?
A. The objective is a diverging lens. B. The eyepiece is a diverging lens. C. The final image is real. D. The image formed by the objective is virtual. E. The image formed by the objective is real.
A particle (charge = +40 ?C) is located on the x axis at the point x = ?20 cm, and a second particle (charge = ?50 ?C) is placed on the x axis at x = +30 cm. What is the magnitude of the total electrostatic force on a third particle (charge = ?4.0 ?C) placed at the origin (x = 0)?
a. 41 N b. 16 N c. 56 N d. 35 N e. 72 N
A proton moving horizontally enters a region where a uniform magnetic field is directed perpendicular to the proton’s velocity as shown in Figure OQ29.4. After the proton enters the field, it
The vertical displacement of a string is given by y(x,t) = (6.00 mm) cos[(3.25 m-1)x - (7.22 s-1)t]. What is the speed of the wave?
A) 0.450 m/s B) 1.41 m/s C) 2.22 m/s D) 3.16 m/s E) 23.5 m/s