Let's solve each problem step by step:
---
Problem 1: Convert 4 milligrams to grams
-
Given: 4 milligrams
-
To find: The equivalent in grams
-
Conversion factor: 1 gram = 1000 milligrams, so 1 milligram = \( \frac{1}{1000} \) grams.
\[
4 \text{ milligrams} = 4 \times \frac{1}{1000} \text{ grams} = 0.004 \text{ grams}
\]
Correct answer:
D. 0.004 grams
---
Problem 2: How many centimeters are in 1 decimeter?
-
Given: 1 decimeter
-
To find: The equivalent in centimeters
-
Conversion factor: 1 decimeter = 10 centimeters
\[
1 \text{ decimeter} = 10 \text{ centimeters}
\]
Correct answer:
B. 10 centimeters
---
Problem 3: Write 3,400 in scientific notation
-
Given: 3,400
-
To find: The number in scientific notation
-
Scientific notation format: A number between 1 and 10 multiplied by a power of 10.
\[
3,400 = 3.4 \times 10^3
\]
Correct answer:
A. 3.4 × 10³
---
Problem 4: Which instrument is best to measure the thickness of paper?
-
Given: Four instruments are shown:
- A: Vernier caliper
- B: Micrometer
- C: Ruler
- D: Wooden stick
-
To find: The best instrument for measuring the thickness of paper
-
Explanation:
- Paper is very thin, so a precise instrument is needed.
- A
micrometer is specifically designed for measuring very small thicknesses (e.g., the thickness of a sheet of paper).
- A vernier caliper can also measure small thicknesses but is less precise than a micrometer.
- A ruler or wooden stick cannot measure such small thicknesses accurately.
Correct answer:
B. Micrometer
---
Problem 5: Which of the following is considered as the absolute temperature?
-
Given: Four temperature scales:
- Fahrenheit
- Rankine
- Celsius
- Kelvin
-
To find: The absolute temperature scale
-
Explanation:
-
Absolute temperature is a temperature scale where zero represents the absence of thermal energy (absolute zero).
- The Kelvin scale is the only absolute temperature scale, starting at absolute zero (0 K).
- Fahrenheit, Celsius, and Rankine are not absolute scales.
Correct answer:
D. Kelvin
---
Final Answers:
1.
D. 0.004 grams
2.
B. 10 centimeters
3.
A. 3.4 × 10³
4.
B. Micrometer
5.
D. Kelvin
Boxed Final Answer:
\[
\boxed{D, B, A, B, D}
\]
Parent Tip: Review the logic above to help your child master the concept of science worksheet for 7th grade free.
