Your grandfather has enjoyed good vision for most of his 80 years. You observe him having trouble reading websites on his new iPad, squinting while he moves it towards and away from his face. You realize he might benefit from reading glasses. Since you were going out anyway, you offer to pick up a pair of glasses for him at the drug store. Consider that your grandfather is at his most comfortable reading posture when he is holding the iPad at a distance of 18 inches.

a. What dioptric power of reading glasses should you get for your grandfather? Note that reading glasses are normally available in increments of 0.25 Diopter.

b. It occurs to you that you could have just shown grandpa how to make the displayed content appear larger on the iPad by adjusting the display "zoom". What percentage zoom (100% is the default view, 200% would make text and images twice as large) would give your grandfather a similar viewing experience to wearing the reading glasses you were planning to purchase?

Answers

Answer 1

Answer:

Step-by-step explanation:

Given that:

The focal point = 18 inches

= (18 × 0.0254)m

= 0.4572 m

= 45.7 cm

For such a comfortable distance of 45.7 cm, the perfect lens power for grandfather can be determined.

Let's recall that, the accommodation amplitude usually decreases with age and eventually becomes 1 D after the age of 50.

Thus, +2.5D  or a convex lens appears to be a perfect one.

b. We will agree that Diopter illustrates the optical power or most at times the capability of the lens.

So, 3D is equally 1.75X magnification which is likely to be double the zoom as it will be helpful to the grandfather.

Now, for a 2.5D, approximately 1.5X zooming once(200%) will be perfect and equal to viewing with the reading glasses.


Related Questions

What types of numbers are Irrational numbers? A)Whole Numbers (positive and negative) B)Repeating Decimals C)Decimals that Terminate D)Decimals that never end​

Answers

Answer:

Whole numbers, repeating decimals, and decimals that never end

Step-by-step explanation:

which orded pair is a solution of the equation 2x+4y=6x-y

Answers

y=4/5x hope that’s the right answer

Fill in the blank to make the two fractions equivalent.
4/7 = ?/28

Answers

Answer:

16

Step-by-step explanation:

28/7 = 4

4 x 4 = 16

16/28 = 4/7

cuál es el número entero de 2° bajo Cero​

Answers

Answer:

 -2 °C.

Step-by-step explanation:

Usa el signo + para representar temperaturas arriba de cero y el signo – para representar temperaturas bajo cero.

What is the probability that the red die shows a six or the green die shows a six?

Answers

Answer:

[tex]\frac{11}{36}[/tex]

Step-by-step explanation:

= 1/6 + 1/6 - 1/6^2

x^2 and -x^2 for x =-3

Answers

Answer:

9 and -9

Step-by-step explanation:

x^2:

all you have to do is (-3)^2 = -3 * -3 = 9

-x^2:

this would be -(-3)^2

the order of operations says to do exponents first, so you would have:

-(9) or -9

6 grade math pls help and do step by step

Answers

Jay didnt follow the BEDMAS rule, he should have started withe the division because it has the priority based on the BEDMAS rule.

Can someone please help me understand this and the answer​

Answers

Answer:

x ≤ 2

Step-by-step explanation:

Calculate the distance between the points A=(-5, 6) and J = (1, -1) in the coordinate plane.

Answers

Answer:

7 cubic meters away

Step-by-step explanation:

I need some help plz!!!

Answers

1.04 kilograms

1 gram = .001 kilogram
2x520= 1040
1040 x .001 = 1.04 kilograms

If f(x) = (3+x)/ (x-3),what is f(a+ 2)?

Answers

To answer items such as this, we directly substitute the a + 2 to the all the x's in the function such that,
f(a + 2) = (3 + a + 2) / (a + 2 - 3)
Simplifying the function generated above,
f(a + 2) = (5 + a) / (a - 1)

15 PTS !!
NEED ASAP HELP !!

Answers

Answer:

314.16 m^2

Step-by-step explanation:

A 31-m tall building casts a shadow. The distance from the top of the building to the tip of the shadow is 33 m. Find the length of the shadow. If necessary,
round your answer to the nearest tenth.
B
5
?

Answers

Answer:

Step-by-step explanation:

[tex]\text{By the Pythagorean Theorem the hypotenuse of a right triangle squared is equal to the sum of the squared sides.}\\ \\ h^2=x^2+y^2\\ \\ 33^2=31^2+x^2\\ \\ x^2=33^2-31^2\\ \\ x^2=128\\ \\ x=\sqrt{128}\\ \\ x\approx 11.3m[/tex]

Howwwwww do I solve this plssssss

Answers

Answer:

Step-by-step explanation:

Which of the following is the correct factorization of -y²+y+6?

Answers

Answer:

(−y−2)(y−3)

Step-by-step explanation:

I'm just going to factor it for you.

Factor −y^2+y+6

−y^2+y+6

=(−y−2)(y−3)

Answer:

(−y−2)(y−3)

(2x+y=-2
5x + 3y = -8
Solve by elimination

Answers

Answer:

y = -6, x =2

Step-by-step explanation:

To solve by elimination, you have to line both equations up together. Then, you multiply both equations until one variable is removed.

2x+y = -2

5x + 3y = - 8

There are many different ways to solve an elimination problem, but generally you should look for the simplest route. Here, I would multiply the top equation by -3.

-6x -3y = 6

5x +3y = -8

Imagine you are adding the two equations together. You end up with

-x = -2

Then solve for x. In this situation, it is fairly simple. Take out a factor of -1.

x = 2

Finally, choose one of your beginning equations and plug your new-found x value back into the equation.

2(2) +y = -2

4 + y = -2

y = -6

Cruz is the editor of a magazine.
The magazine has 40 pages.

The magazine must have:
20% of the pages for adverts
1/4 of the pages for photos
the remaining pages for articles.

Work out the number of pages for articles in the magazine.
Show your working out.

Answers

Answer:

22

Step-by-step explanation:

20% * 40 = 20 / 100 * 40 = 800 / 100 = 8

1/4 * 40 = 40 / 4 = 10

So far we have use 8 + 10 = 18

There are 40 - 18 pages left

articles = 22

what was the main difference between the French and British armies in the French and Indian War ​

Answers

The French had many alliances with the Indians and the British had more troops. The French has to deal with untrained troops.


Hope this helps :)

Help plzzzz helppp heppppdidjjdhjrbrbfnd meeee

Answers

Answer:

The large one

Step-by-step explanation:

If she  used the WHOLE thing in the large one and HALF in the smaller one then that means there is more in the large one and that it is more choclete.

Answer:

The larger one!

Step-by-step explanation:

Simplify the algebraic expression (8x + 16y)/2 + 4(x - y)

Answers

It's 8x + 16y/2 + 4x - 4y :))

Answer:

8x+4y

Step-by-step explanation:

Distribute:

=4x+8y+(4)(x)+(4)(−y)

=4x+8y+4x+−4y

Combine Like Terms:

=4x+8y+4x+−4y

=(4x+4x)+(8y+−4y)

=8x+4y

Answer:

=8x+4y

I hope I helped!!

a bottle of orange juice holds for 4/6 quarts of juice. a bottle of pineapple juice holds 2/3 quarts of juice. which bottle has more juice ​

Answers

Answer:

the orange juice has more ounces than the pineepple juice

Step-by-step explanation:

Find the missing length in the right triangle.


Answers

Answer:

10 ft

Step-by-step explanation:

By using the pythagorean theorem, we know that leg1 squared plus leg2 squared is equal to hypotenuse squared.

[tex]6^2+8^2=?^2\\36+64=?^2\\100=?^2\\10=?[/tex]

Answer: 10ft

Step-by-step explanation:

Pythagorean Theorem- In a right triangle, a²+b²=c² where: (image attached)

a=6ft ; b=8ft

6ft²= 36ft ; 8ft²= 64ft

36+64=100ft

√100= 10ft

A highway department is studying the relationship between traffic flow and speed. The following model has been hypothesized. where traffic flow in vehicles per hour vehicle speed in miles per hour The following data were collected during rush hour for six highways leading out of the city. Traffic Flow () Vehicle Speed () 1257 36 1329 45 1227 30 1336 50 1349 55 1124 25 a. Use the data to compute the coefficients of this estimated regression equation (to decimals). Enter negative value as negative number. (Create the variable first using Data/Transform

Answers

Answer:

ŷ = 0.1286X - 123.2175 ;

R = 0.9465

R² = 0.8958

Step-by-step explanation:

Given the data:

Traffic Flow, X : ()

1257

1329

1227

1336

1349

1124

Vehicle speed, Y () :

36

45

30

50

55

25

The estimated regression equation using a linear regression calculator is given thus:

ŷ = 0.1286X - 123.2175

According to the general linear regression formula :

y = mx + c

Where ; y = predicted variable (vehicle speed)

x = predictor variable (traffic flow)

Slope, m = 0.1286

Intercept, c = 123.2175

The correlation Coefficient, R = 0.9465, This depicts a strong positive relationship between traffic flow and vehicle speed.

The Coefficient of determination, R² = 0.9465² = 0.8958 ; This means about 89.5% of variation in Vehicle speed can be explained by the regression line.

Which of the following is most likely the next step in the series ?​

Answers

Answer:

A

Step-by-step explanation:

The colour keeps switching from red to blue to red, and red was last in the series. Therefore, a blue pattern should be next in the series.

Each time, a new hand is added to the pattern. Therefore, we add a hand.

The answer is definitely A.

Find the equation of this line

Answers

Answer: y=1x+1

Step-by-step explanation:

Rise/Run = 1/1 = 1 = slope

y-intercept : 1

Answer:

y=-2x+1 is the answer

Step-by-step explanation:

what is the variable in this expression 5x2+x+7?

Answers

Answer:

x

Step-by-step explanation:

Julissa earns $13 per hour. If her regular hours are 40 hours per week, and she receives double time overtime,
find her total pay for a week in which she works 45 hours.

Answers

Answer:

1,040 dollars

Step-by-step explanation:

Alex has 100. He spends 3/10of it on candies. He spends one-seventh of what's left on colour pencils. How
much money is Alex left with?​

Answers

Answer:

$60

Step-by-step explanation:

3 tenths of 100 is 30

1 * 10 is 10

100 - 30 + 10

= 100 - 40

= $60

3x+2=14 what number makes the equation true?

Answers

Answer:

Step-by-step explanation:

3x+2=14 subtract 2 from both sides

3x=12 divide both sides by 3

x=4

PLEASE ANSWER THIS QUESTION!!!!!!!!!!!!!

uhhh... my math grade is a D and i dont have my phone and i want it back so please just help me, this will get my grade up to a C or a B at least so help

Answers

Answer:

function one

Step-by-step explanation:

the x intercept in function one is a negative number

Answer: function one

Step-by-step explanation:

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