Finding the surface area of a balloon

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Olivia Rose 2022-3-19

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1675609-finding-the-surface-area-of-a-balloon

评论： Voss 2022-3-19

This is the problem I'm working on. I think I have everything written out correctly, but I'm having trouble putting it all together.

回答（1 个）

Voss 2022-3-19

1
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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1675609-finding-the-surface-area-of-a-balloon#answer_921939

编辑：Voss 2022-3-19

在 MATLAB Online 中打开

surfaceBalloon(1,[1:3]) % check consistency with the prompt

ans = 1×3

5.0004 5.1214 5.3785

M = linspace(0,6,100); % calculate and generate plot

plot(M,surfaceBalloon(14000,M));

function A = surfaceBalloon(V,M)

% V = pi*R^3*(2+M)/3

R = (3*V/pi./(2+M)).^(1/3); % calculate R first

A = pi*R.^2.*(2+sqrt(1+M.^2)); % then calculate A

end

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Torsten 2022-3-19

编辑：Torsten 2022-3-19

在 MATLAB Online 中打开

Yes, the correct function you should use is

function surfaceArea = surfaceBalloon(V,M)
% V = pi*R^3*(2+M)/3
R = (3*V/pi./(2+M)).^(1/3); % calculate R first
surfaceArea = pi*R.^2.*(2+sqrt(1+M.^2)); % then calculate A
end

instead of yours.

The task was to return the surface area for an arbitrary volume. You assume V = 14000, I guess.

I did not check whether the other calculations are ok.

Voss 2022-3-19

@Danielle Reis I see. I thought maybe you had modified your function based on the answers you've seen here.

The function I posted has an output argument, called A in my version (called surfaceArea in @Torsten's version).

In my answer, I use the output from the function directly in plot(); it is not assigned to a variable in the calling workspace. Of course you can assign its output to a variable if that is a requirement.

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