Physics question from DM exam

[J.R.]

... ah... but what would the NAUI answer be???

Sorry... couldn't resist.

 

[NudeDiver]

I find it fascinating that some very intelligent people are construing this sentence to mean how much weight is required to make the object 50 pounds negative. That is not what the sentence says at all. Whether it is what the original question said, or whether it is what the original question MEANT, we don't know. But it is not what THIS question says. It says we are ADDING 50 lbs of negative buoyancy, which requires 50 lbs of lead.

People are just reading it to mean what they want it to mean, rather than what it actually says.

 

[NudeDiver]

If Johnny only has 3 apples how can you take away 50?

Go back and read again, you'll find out why.

 

[Gombessa]

I find it fascinating that some very intelligent people are construing this sentence to mean how much weight is required to make the object 50 pounds negative. That is not what the sentence says at all. Whether it is what the original question said, or whether it is what the original question MEANT, we don't know. But it is not what THIS question says. It says we are ADDING 50 lbs of negative buoyancy, which requires 50 lbs of lead.

If we're strict with logic, the answer is clear and simple - 50#, full stop. But the people saying 53# are not interested in logic, they're interested in answering the intended question. While I can applaud that, I certainly wouldn't want them drafting or reviewing my contracts

It almost certainly was miswritten or misremembered in the original question. But the answer is simple, and Sparticle, I'm surprised at you! Parse the sentence.

Spart, if your fiancee is going to law school now, why not pass this question by her and see what she says? I guarantee you that this is a softball for anyone who's studied for the LSAT.

 

[Gombessa]

Re-read the question.

What amount of lead would be required to add 50 lbs of negative buoyancy to the object?

Meaning that they want the object to be 50 lbs NEGATIVE. If the object is starting off 3 lbs positive to begin with, then you need to add 53 lbs of lead to make the object 50 lbs negative.

Maybe it would help to use the same language in a more familiar context:

A regulator costs a total of $200. What amount of dollars would be required to add 50 dollars of cost to the object?

There's no way to correctly interpret that as asking for the amount required to make the total cost of the regulator $50.

Simply, as the question was originally worded, it's not a matter of math or physics, it's a matter of logic and reading comprehension. Which is why it was not likely the question asked on the DM test.

 

[Peter Guy]

Re: Johnny and taking away 50 apples. In the original post it says "Johnny has 3 apples...." It doesn't say that Johnny ONLY has 3 apples. IF he has at least 50, one could properly say he "has 3 apples" (he does) AND one could take 50 apples away from him.

The perfect lawyer answer.

 

[TSandM]

Re: Johnny and taking away 50 apples. In the original post it says "Johnny has 3 apples...." It doesn't say that Johnny ONLY has 3 apples. IF he has at least 50, one could properly say he "has 3 apples" (he does) AND one could take 50 apples away from him.

The perfect lawyer answer

I live with this.

Sparty, you're going to live with this, too.

 

[eponym]

Wow I finally won an argument (I think), wish I could do the same; just once, with my wife...

If a man states a position and his wife is not around to hear it, is he still wrong?

-Bryan

PS This thread gets my vote for most entertaining this month. For more on Adams's 42, see this wiki article.

 

[dumpsterDiver]

Re: Johnny and taking away 50 apples. In the original post it says "Johnny has 3 apples...." It doesn't say that Johnny ONLY has 3 apples. IF he has at least 50, one could properly say he "has 3 apples" (he does) AND one could take 50 apples away from him.

The perfect lawyer answer.

Do you mean Johny has only 3 apples? Because if Johhny only has 3 apples, that means he has nothing else and I'm definitely not taking apples from a naked guy.

 

[amascuba]

Maybe it would help to use the same language in a more familiar context:

A regulator costs a total of $200. What amount of dollars would be required to add 50 dollars of cost to the object?

There's no way to correctly interpret that as asking for the amount required to make the total cost of the regulator $50.

Simply, as the question was originally worded, it's not a matter of math or physics, it's a matter of logic and reading comprehension. Which is why it was not likely the question asked on the DM test.

While i've read what others are saying about just adding 50lbs of ballast and I can see where they would get that. Apparently English isn't my first language after all.

The way that I first read the question and would still interperet is that they are wanting to make the object 50 lbs negative when it states "add 50 lbs of negative buoyancy". When I read that, my mind automatically starts down the path of Archimedes Principle and how much ballast I would need to add to make it 50 lbs negative.

It's all in how you percieve the problem. Not how you want the problem to work, as somebody would like you to believe.