Converting the length of a sound to seconds
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. A sound file is 3 minutes long. How many seconds should you use in a file size calculation?
2. Which formula correctly converts minutes to seconds?
3. A recording lasts 2 minutes 30 seconds. What length do you use in the calculation?
4. Sound file size = sample rate x sample resolution x length. What must the length be measured in?
5. A song is 4 minutes long. Which working is correct for the length factor?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1seconds = 3 * 60 | Asize = 44100 * 16 * (4 * 60) | |
| 2seconds = 2 * 60 + 30 | BConverts a sound of 3 minutes into 180 seconds before using it in the file size formula | |
| 3Length is the third factor in the formula, so it must be in seconds: file size = sample rate x sample resolution x length in seconds | Clength = 1 * 60 + 20 | |
| 4A sound lasting 1 minute 20 seconds must be changed to seconds before it is used in a calculation | DThe sound is 5 minutes long but 5 was used as the length, so the minutes were never converted to seconds. It should be 5 * 60 = 300. | |
| 5size = 8000 * 8 * 5 | EConverts a sound of 2 minutes 30 seconds into 150 seconds by multiplying the minutes by 60 and adding the extra seconds | |
| 6seconds = 2 * 60 * 30 | FThe extra 30 seconds were multiplied instead of added. For 2 minutes 30 seconds it should be 2 * 60 + 30 = 150. |
C
Definitions
seconds = minutes x 60
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
seconds = minutes * __
2.
seconds = _______ * 60
3.
# 3 minutes 20 seconds
seconds = 3 * 60 + __
4.
size = rate * resolution * _______
5.
seconds = minutes _ 60
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
minutes ← 3
B
extra ← 20
C
seconds ← minutes * 60 + extra
D
size ← rate * res * minutes
Question 2
A
minutes ← 2
B
seconds ← minutes * 100
C
rate ← 44100
D
bits ← rate * 16 * seconds
Question 3
A
minutes ← 5
B
extra ← 30
C
seconds ← minutes * 60 - extra
D
OUTPUT seconds
Question 4
A
minutes ← 4
B
seconds ← minutes * 60
C
bits ← 8000 * 8
D
bits ← bits + seconds
Question 5
A
minutes ← 1
B
seconds ← minutes / 60
C
size ← 8000 * 16 * seconds
D
OUTPUT size
Answer Key
Converting the length of a sound to seconds
Section A: Quick Questions
Q1
B — 180 seconds
Q2
A — seconds = minutes x 60
Q3
B — 150 seconds
Q4
A — Seconds
Q5
A — 4 x 60 = 240
Section B: Match the Pairs
Q1
seconds = 3 * 60 → Converts a sound of 3 minutes into 180 seconds before using it in the file size formula
Q2
seconds = 2 * 60 + 30 → Converts a sound of 2 minutes 30 seconds into 150 seconds by multiplying the minutes by 60 and adding the extra seconds
Q3
Length is the third factor in the formula, so it must be in seconds: file size = sample rate x sample resolution x length in seconds → size = 44100 * 16 * (4 * 60)
Q4
A sound lasting 1 minute 20 seconds must be changed to seconds before it is used in a calculation → length = 1 * 60 + 20
Q5
size = 8000 * 8 * 5 → The sound is 5 minutes long but 5 was used as the length, so the minutes were never converted to seconds. It should be 5 * 60 = 300.
Q6
seconds = 2 * 60 * 30 → The extra 30 seconds were multiplied instead of added. For 2 minutes 30 seconds it should be 2 * 60 + 30 = 150.
Section C: Definitions
Q1
seconds = minutes x 60 — Sound length must be in seconds before using it in a file size calculation, so multiply minutes by 60 (add any extra seconds). Length is then the third factor in the formula.Section D: Fill in the Blanks
Q1
seconds = minutes * 60Q2
seconds = minutes * 60Q3
# 3 minutes 20 seconds
seconds = 3 * 60 + 20Q4
size = rate * resolution * secondsQ5
seconds = minutes * 60Section E: Spot the Error
Q1
D — The length must be in seconds before it is used in the file size formula. The line should multiply by seconds, not minutes.
Q2
B — There are 60 seconds in a minute, not 100. It should be seconds ← minutes * 60.
Q3
C — Extra seconds must be added to the converted minutes, not subtracted. It should be minutes * 60 + extra.
Q4
D — The length in seconds is the third factor and is multiplied with the sample rate and sample resolution. It should be bits * seconds, not bits + seconds.
Q5
B — Converting minutes to seconds needs multiplication, not division. It should be seconds ← minutes * 60.