Let's solve each problem step by step with clear explanations.
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Problem 5: Density of Himalayan Salt
Given:
- Dimensions: 20 cm × 10 cm × 4 cm
- Mass: 1 kg and 600 g
Step 1: Convert mass to grams
- 1 kg = 1000 g
- So, total mass = 1000 g + 600 g =
1600 g
Step 2: Calculate volume
- Volume = length × width × height
- Volume = 20 cm × 10 cm × 4 cm =
800 cm³
Step 3: Use density formula
- Density (D) = mass / volume
- D = 1600 g / 800 cm³ =
2.0 g/cm³
✔ Answer:
- mass =
1600 g
- volume =
20 × 10 × 4 = 800 cm³
- D = 1600 g / 800 cm³ → Its density is:
2.0 g/cm³
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Problem 6: Density of Lead Brick
Given:
- Same dimensions: 20 cm × 10 cm × 4 cm
- Mass: 9 kg and 120 g
Step 1: Convert mass to grams
- 9 kg = 9000 g
- Total mass = 9000 g + 120 g =
9120 g
Step 2: Volume (same as before)
- Volume = 20 × 10 × 4 =
800 cm³
Step 3: Calculate density
- D = 9120 g / 800 cm³ =
11.4 g/cm³
✔ Answer:
- mass =
9120 g
- volume =
20 × 10 × 4 = 800 cm³
- D = 9120 g / 800 cm³ → Its density is:
11.4 g/cm³
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Problem 7: Which liquid floats on top?
Given:
- Liquid A: density = 0.75 g/cc
- Liquid B: density = 1.14 g/cc
Concept:
- Less dense liquids float on top of more dense liquids.
- Since 0.75 < 1.14,
liquid A is less dense.
✔ Answer:
- Solution:
Liquid A floats on top of liquid
B
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Problem 8: Compare densities of two erasers
####
Eraser 1:
- Mass = 3 g
- Volume = 1 cm³
- Density = 3 g / 1 cm³ =
3.0 g/cm³
####
Eraser 2:
- Mass = 3 g
- Volume = 3 cm³
- Density = 3 g / 3 cm³ =
1.0 g/cm³
Comparison:
- Eraser 1 has higher density (3.0 > 1.0)
✔ Answer:
- First eraser (mass 3g, volume 1cm³):
D = 3 g / 1 cm³ → Density =
3.0 g/cm³
- Second eraser (mass 3g, volume 3cm³):
D = 3 g / 3 cm³ → Density =
1.0 g/cm³
- Solution: The
first eraser has a greater density
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✔ Final Answers Summary:
5. Himalayan Salt:
- mass =
1600 g
- volume =
800 cm³
- Density =
2.0 g/cm³
6. Lead Brick:
- mass =
9120 g
- volume =
800 cm³
- Density =
11.4 g/cm³
7. Floating Liquids:
-
Liquid A floats on top of
Liquid B
8. Erasers:
- First eraser:
3.0 g/cm³
- Second eraser:
1.0 g/cm³
- The
first eraser has greater density
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Parent Tip: Review the logic above to help your child master the concept of 5th grade density worksheet.
