Surface area of N spherical droplets?

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SUMMARY

The problem involves calculating the total surface area of N spherical droplets formed from 30.0 cm³ of gasoline, with each droplet having a radius of 2.00 x 10^-3 m. The surface area (SA) of a single droplet is calculated using the formula SA = 4 * π * r², resulting in an individual surface area of 5.03 x 10^-9 m². The total volume of the droplets can be determined using the volume formula V = 4/3 * π * r³, leading to the conclusion that the total volume before atomization equals the total volume after. By equating the known volume of gasoline to the volume of the droplets, the number of droplets (N) can be derived, allowing for the calculation of the total surface area.

PREREQUISITES
  • Understanding of geometric formulas for surface area and volume of spheres
  • Familiarity with unit conversions (cm³ to m³)
  • Basic algebra for solving equations
  • Knowledge of constants such as π (pi)
NEXT STEPS
  • Calculate the total volume of N spherical droplets using the formula V = N * (4/3 * π * r³)
  • Explore the implications of surface area in fluid dynamics and atomization processes
  • Investigate the effects of droplet size on combustion efficiency in gasoline engines
  • Learn about the applications of spherical droplet calculations in chemical engineering
USEFUL FOR

Students in physics or engineering, particularly those studying fluid mechanics, as well as professionals involved in combustion research and atomization technology.

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Homework Statement



I have the following problem
Assume that 30.0 cm^3 of gasoline is atomized into N spherical droplets, each with a radius of 2.00 x 10^-3 m. What is the total surface area of these N spherical droplets?

Homework Equations


SA = 4 * pi *r^2
V = 4/3 * pi * r^3

The Attempt at a Solution


SA of each atom is 5.03x10^-9
V = 3.35x10^-14
 
Last edited:
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Ok, think about this.

What is the total surface area of all the spheres in terms of N?

What is the total volume of all the spheres in terms of N?

If you can answer these questions you should be able to eliminate N, allowing you to solve for The surface area.
 
Have you worked out how many droplets there are?
 
Ignoring the fact both SA and V of the droplets are both very wrong and lack units (you can do better than that!). Total volume before equals total volume after. Use that to solve for N.
 
The values are wrong...?
I know the units of area of is m sqrd and volume is m cubed, but as far the values go, has my calculator betrayed me?
 
Last edited:
You are given a volume of gasoline and told it is turned into N small spheres. You are given the radius of the spheres and thus you can work out the volume and surface area. You know what the volume is and so you can find out how many droplets there are. Then you can find the total surface area.
 
Muahahahahaa! I got it :)
I am going to go ahead and say I love you guys. Thank you for all your help.
Next time you guys are in germany, bring lots of lube.
 
Last edited:

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