Dimensional analysis Problems

In summary, a student is asking for help with three problems involving density and conversions. The first problem asks for the mass of a liquid given its density and volume. The second problem involves using the formula for density to determine the density of a liquid. The final problem requires converting units and using the formula for density to calculate the dustfall rate in milligrams per square meter per month. The student has attempted the third problem but is struggling with the concepts and asking for assistance.
  • #1
montagical
1
0

Homework Statement


I have a few problems that I'm unsure how to proceed with...

1. Ethylene glycol, and antifreeze, has a density of 1.1 g/cm^3. What is the mass, in grams, of 417 mL of this liquid? 1 cm^3 = 1 mL

2. To determine the density of a liquid, a flask is weighed empty (108.6g) and again when filled with 125 mL of a liquid (207.5g). What is the density of the liquid?

3. One ton is equal to 2000 pounds, 2.205 pounds = 1 kilogram. A typical rate of deposit of dust ("dustfall") from air that is not significantly polluted might be 3.86 tons per square kilometer per month. What is this dustfall, expressed in milligrams per square meter per month?




My attemps at number 3!

The only one I'm able to do, is the third one.

Here's my work, as best I can write here:

3.86tons/km^2/month x 2000lbs/1ton x 1kg/2.205lbs. x 1000m^2/1km^2 x 1000000mg/1kg

3.86 x 2000 x 1000000 x 1000/2.205

3.501133787 x 10^12 mg/m^2 /month is the answer that I got.

Unfortunately our teacher did not do a very good job teaching us DA...

Thanks for any help,

montagical
 
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  • #2
Relevant formula you will need is ρ=M/V OR Density=Mass/Volume
 
  • #3



Dear montagical,

Thank you for reaching out for help with your dimensional analysis problems. I am happy to assist you in understanding and solving these problems.

1. To solve this problem, we can use the conversion factor: 1 cm^3 = 1 mL. This means that 417 mL is equal to 417 cm^3. We can then use the given density of ethylene glycol (1.1 g/cm^3) to set up a dimensional analysis equation:

417 cm^3 x 1.1 g/cm^3 = 458.7 g

Therefore, the mass of 417 mL of ethylene glycol is 458.7 grams.

2. In this problem, we are given the weight of an empty flask (108.6g) and the weight of the flask when filled with 125 mL of liquid (207.5g). We can use the difference in weight (207.5g - 108.6g = 98.9g) to determine the weight of the liquid. We can then use the given volume of 125 mL to set up a dimensional analysis equation:

98.9g x 1 mL/125 mL = 0.7912 g/mL

Therefore, the density of the liquid is 0.7912 g/mL.

3. To solve this problem, we need to convert all units to a common unit (milligrams per square meter per month). We can use the following conversion factors: 1 ton = 2000 pounds, 1 pound = 0.4536 kilograms, and 1 square kilometer = 1,000,000 square meters.

3.86 tons/km^2/month x 2000 lbs/ton x 0.4536 kg/lb x 1,000,000 m^2/km^2 x 1,000,000 mg/kg = 3.501 x 10^12 mg/m^2/month

Therefore, the dustfall expressed in milligrams per square meter per month is 3.501 x 10^12 mg/m^2/month.

I hope this helps you to better understand and solve these dimensional analysis problems. If you have any further questions, please don't hesitate to ask. Keep up the hard work in your studies!

Best,
 

1. What is dimensional analysis and why is it important in scientific research?

Dimensional analysis is a mathematical technique used to convert units from one system to another. It is important in scientific research because it helps ensure that calculations and measurements are accurate and consistent, and it allows for easy comparison and communication of results between scientists.

2. How do you set up and solve a dimensional analysis problem?

To set up a dimensional analysis problem, you need to identify the given unit and the desired unit for conversion. Then, list out all the conversion factors needed to go from the given unit to the desired unit. Finally, cancel out the units to get the final conversion. To solve the problem, simply multiply all the numbers together and divide by all the units that cancel out.

3. Can dimensional analysis be used for any type of unit conversion?

Yes, dimensional analysis can be used for any type of unit conversion as long as the units are compatible. This means that the units being converted must measure the same physical quantity, such as length, time, mass, or volume.

4. What are some common mistakes to avoid in dimensional analysis problems?

One common mistake in dimensional analysis is using the wrong conversion factor. It is important to double-check that the conversion factor is going in the correct direction and that the units cancel out correctly. Another mistake is forgetting to include all units in the calculation, which can lead to incorrect results.

5. How can dimensional analysis be applied in real-life situations?

Dimensional analysis can be applied in real-life situations such as cooking, construction, and medicine. For example, converting recipes from one unit of measurement to another, calculating materials needed for a construction project, and administering the correct dosage of medication based on a patient's weight all require the use of dimensional analysis.

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