# Finding apparent depth real depth and refractive index

• RabbitWho
In summary, the conversation discusses finding the apparent depth in water using the refractive index and the real depth. The correct method involves multiplying both sides by x, or using cross multiplication or inversion methods.
RabbitWho

## Homework Statement

refractive index = 1.33 (water)
real depth = 10m

## Homework Equations

refractive index = real depth divided by apparent depth

## The Attempt at a Solution

I'm going to call apparent depth X

1.33 = 10/x

So I multiply 10/x by 10 so that i have x and 1.33 x 10 is 13.3... that's right, isn't it? but that makes no sense, because the apparent depth must be less than the actual depth.

I know the real answer is 7.52.. what am I doing wrong?

No idea if the problem is with my maths or my physics.

RabbitWho said:
So I multiply 10/x by 10 so that i have x and 1.33 x 10 is 13.3... that's right, isn't it?
No, not right. If you multiply ##\frac{10}{x}## by 10 you get ##\frac{100}{x}##.

You need to get that x out of the denominator, so multiply both sides by x, not 10. (Or you can cross multiply. Or you can invert both sides. Many ways to play the game!)

RabbitWho
Thank you! that makes sense. I got the answer right now :)

## What is the concept of apparent depth?

Apparent depth refers to the perceived depth of an object when viewed through a medium, such as water or glass. It is different from the actual depth of the object and is affected by the refractive index of the medium.

## What is real depth?

Real depth is the actual distance between the observer and the object. It is not affected by the medium through which it is viewed.

## What is the relationship between apparent depth and real depth?

The apparent depth is always less than the real depth when viewing an object through a medium due to the bending of light rays caused by the change in speed of light in the medium.

## How do you calculate the refractive index of a medium?

The refractive index of a medium can be calculated by dividing the speed of light in a vacuum by the speed of light in the medium. It is represented by the symbol "n" and is a unitless quantity.

## What factors can affect the refractive index of a medium?

The refractive index of a medium can be affected by factors such as temperature, pressure, and the type of material the medium is made of. Higher temperatures and pressures can increase the refractive index, while different materials have different natural refractive indices.

• Optics
Replies
5
Views
2K
• Optics
Replies
3
Views
3K
• Precalculus Mathematics Homework Help
Replies
3
Views
2K
• Introductory Physics Homework Help
Replies
8
Views
1K
• Introductory Physics Homework Help
Replies
1
Views
3K
• Introductory Physics Homework Help
Replies
8
Views
3K
• Introductory Physics Homework Help
Replies
3
Views
1K
• Introductory Physics Homework Help
Replies
5
Views
1K
• Precalculus Mathematics Homework Help
Replies
9
Views
2K
• Introductory Physics Homework Help
Replies
3
Views
1K