Determine the number of N of digital bits

In summary, on an audio compact disc (CD), digital bits of information are encoded sequentially along a spiral path. Each bit occupies about 0.28 um. A CD player's readout laser scans along the spiral's sequence of bits at a constant speed of about 1.2 m/s as the CD spins.
  • #1
tavo0116
21
0
On an audio compact disc (CD), digital bits of information are encoded sequentially along a spiral path. Each bit occupies about 0.28 um. A CD player's readout laser scans along the spiral's sequence of bits at a constant speed of about 1.2 m/s as the CD spins.

Determine the number N of digital bits that a CD player reads every second.

How should I start on this problem. Thank you !
 
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  • #2
tavo0116 said:
On an audio compact disc (CD), digital bits of information are encoded sequentially along a spiral path. Each bit occupies about 0.28 um. A CD player's readout laser scans along the spiral's sequence of bits at a constant speed of about 1.2 m/s as the CD spins.

Determine the number N of digital bits that a CD player reads every second.

How should I start on this problem. Thank you !

If you had a conveyor belt going past at 5 m/s, and it was loaded with pencils arranged sideways on the belt, touching each other, and each pencil is 4mm in diameter - how many pencils pass each second.

You CD is like that with different sizes involved.
 
  • #3
Just FYI, the phrase "digital bits" is a nonsensical. "Bits" means BINARY digits, not decimal digits.
 
  • #4
PeterO said:
If you had a conveyor belt going past at 5 m/s, and it was loaded with pencils arranged sideways on the belt, touching each other, and each pencil is 4mm in diameter - how many pencils pass each second.

You CD is like that with different sizes involved.

So I would need to convert 5m/s to mm, which will then give me 5000mm/s?
Then in order to fill the number of pencils pass each second, I would take 5000 mm/4 mm, which will then give me 1250 pencils?

As for the problem I posted, um is micrometer, right?
So then I would need to convert 1.2 m/s to 1200000 um/s?

Then as I did before, I would need to take 1200000 um / 0.28 um, which will then give me 42.86E^6?
 
  • #5
tavo0116 said:
So I would need to convert 5m/s to mm, which will then give me 5000mm/s?
Then in order to fill the number of pencils pass each second, I would take 5000 mm/4 mm, which will then give me 1250 pencils?

As for the problem I posted, um is micrometer, right?
So then I would need to convert 1.2 m/s to 1200000 um/s?

Then as I did before, I would need to take 1200000 um / 0.28 um, which will then give me 42.86E^6?

That should be correct [I didn't check the calculation]. though that answer would be marked wrong in our school system. You have merely written down what the calculator said.

You should have said 4.3 x 10^7 [assuming you answer was correct] [or 43 x 10^6 if you are using engineering notation]

As I said, any submitted answer here, with an E in it, marked WRONG.

[and why only 4.3 rather than 4.286?]
 
  • #6
PeterO said:
That should be correct [I didn't check the calculation]. though that answer would be marked wrong in our school system. You have merely written down what the calculator said.

You should have said 4.3 x 10^7 [assuming you answer was correct] [or 43 x 10^6 if you are using engineering notation]

As I said, any submitted answer here, with an E in it, marked WRONG.

[and why only 4.3 rather than 4.286?]

I calculated that, and entered it in the system as 4.3 x 10^7, and it was right.
This was for an online homework problem.

Thank you so much for your help.
Have a great day !
 

1. How is the number of digital bits determined?

The number of digital bits is determined by the number of binary digits (0s and 1s) needed to represent a piece of data. This is based on the power of 2, where each additional bit doubles the number of possible combinations.

2. What factors affect the number of digital bits needed?

The number of digital bits needed can be affected by the size and complexity of the data being represented, as well as the intended use of the data. For example, audio and video files may require more bits than text files.

3. How does the number of digital bits relate to file size?

The number of digital bits can directly affect the file size, as each bit represents a piece of information that needs to be stored. The more bits needed, the larger the file size will be.

4. Can the number of digital bits change over time?

Yes, the number of digital bits needed can change over time as technology advances and storage capabilities increase. For example, a file that required 10 bits to represent in the past may only require 5 bits with the development of more efficient data compression methods.

5. How is the number of digital bits calculated for modern devices?

The number of digital bits needed for modern devices is typically calculated based on the resolution and color depth of the device's display. For example, a smartphone with a 1080x1920 resolution and 24-bit color depth will require 1080 x 1920 x 24 = 49,766,400 bits to display a single image.

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