A nearsighted person has a near point of 12 cm and a far point of 17 cm. If the corrective lens is 2.0 cm from his eye,
(a) what lens power will enable this person to see distant objects clearly, and (b) what then will be the new near point of his eye?
(a) -6.7 diopters (b) 30 cm in front of the lens
You might also like to view...
An object weighs 300 N. If the gravitational constant G were half of what it is currently, what would the weight of the object be?
a. 300 N b. 150 N c. 75 N d. 600 N e. 450 N
What do we mean when we say that the universe is expanding?
A) Average distances between galaxies are increasing with time. B) Within galaxies, average distances between star systems are increasing with time. C) Everything in the universe is gradually growing in size. D) The statement is not meant to be literal; rather, it means that our knowledge of the universe is growing.
Two point charges of +20.0 ?C and -8.00 ?C are separated by a distance of 20.0 cm. What is the magnitude of electric field due to these charges at a point midway between them? (k = 1/4??0 = 8.99 × 109 N • m2/C2)
A) 25.2 × 106 N/C directed toward the negative charge B) 25.2 × 106 N/C directed toward the positive charge C) 25.2 × 105 N/C directed toward the negative charge D) 25.2 × 105 N/C directed toward the positive charge E) 25.2 × 104 N/C directed toward the negative charge
A box slides across a floor and comes to rest. The work done by the frictional force on the box is a. positive
b. negative. c. zero. d. impossible to determine without knowing the coefficient of friction.