1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
erma4kov [3.2K]
2 years ago
15

A person with a near point of 85 cm, but excellent distant vision, normally wears corrective glasses. But he loses them while tr

aveling. Fortunately, he has his old pair as a spare.
(a) If the lenses of the old pair have a power of +2.25 diopters, what is his near point (measured from his eye) when he is wearing the old glasses if they rest 2.0 cm in front of his eye?
(b) What would his near point be if his old glasses were contact lenses instead?
Physics
1 answer:
svp [43]2 years ago
7 0

Answer:

a)   p = 95.66 cm, b) p = 93.13 cm

Explanation:

For this problem we use the  constructor equation

         \frac{1}{f} = \frac{1}{p} + \frac{1}{q}

where f is the focal length, p and q are the distances to the object and the image, respectively

the power of the lens is

         P = 1 / f

         f = 1 / P

         f = 1 / 2.25

         f = 0.4444 m

the distance to the object is

         \frac{1}{p} = \frac{1}{f} -\frac{1}{q}

the distance to the image is

          q = 85 -2

           q = 83 cm

we must have all the magnitudes in the same units

           f = 0.4444 m = 44.44 cm

we calculate

           \frac{1}{p} = \frac{1}{44.44} - \frac{1}{83}

           1 / p = 0.010454

            p = 95.66 cm

b) if they were contact lenses

            q = 85 cm

            \frac{1}{p} = \frac{1}{44.44} - \frac{1}{85}

             1 / p = 0.107375

             p = 93.13 cm

You might be interested in
When the net force of opposite forces is zero , the forces are
lorasvet [3.4K]
The answer is balanced
4 0
3 years ago
The magnitude of a force is:
lys-0071 [83]

Answer:

c

Explanation:

force is how hard it is pulled or pushed

3 0
3 years ago
______ energy is defined as the energy of motion.
MatroZZZ [7]
Kinetic energy is defined as the energy of motion. On the other hand, potential energy is the energy of non-motion.
Hope that helped =)
7 0
3 years ago
Read 2 more answers
NEED HELP ASAP
postnew [5]

Explanation:

TEMPLE HINDUS MOSQUE MUSLIMS TEMPLE HINDUS MOSQUE MUSLIMS

5 0
3 years ago
A pulley lifts a 72-N load with a force of 24-N. The input distance is 2m and the output distance is 0.5m. What is the efficienc
Debora [2.8K]

Answer:

Explanation:

Work done on the lever ( input energy ) = force applied x input distance

= 24 N x 2m = 48 J

Work done by the lever ( output energy ) = load x output distance

= 72 N x 0.5m = 36 J

efficiency = output energy / input energy

= 36 J  / 48 J

= 3 / 4 = .75

In percentage terms efficiency = 75 % .

5 0
3 years ago
Other questions:
  • The total mechanical energy of a system is equally divided between kinetic energy and potential energy. can never be negative. i
    10·1 answer
  • What Is the volume of the rectangular prism of 6cm 9cm and 5cm
    7·1 answer
  • Information gathered from observing a plant grow 3 cm over a two week period is<br> called:
    15·1 answer
  • When a 0.1-kilogram pendulum bob reaches the top of its swing, how much kinetic energy does it have?
    11·1 answer
  • Four equal negative point charges are located at the corners of a square, their positions in the xy-plane being (1,1), (−1,1), (
    14·2 answers
  • ASAP When salt is dissolved in water, the result is a A. gas B. compound C. homogeneous mixture D. heterogeneous mixture
    8·2 answers
  • Akbar and Lucia apply opposing forces on a
    5·1 answer
  • The acceleration of an object would increase if there was an increase in the
    15·1 answer
  • Need help due in 4 minutes
    6·2 answers
  • Can someone please help me with this problem
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!