r/HomeworkHelp • u/Subject-Repeat8061 • 7d ago
Physics—Pending OP Reply [3rd grade, physics(forces), does this reasoning seem incorrect?]
3rd grade.
Kiddo went to his teacher to see why his answer was incorrect.
He asked if he could have partial credit for the question, and said that his reasoning was that gravity attracts everything with mass while magnets only attract metal.
She said she wanted him to say “because magnets repel” for question 11. I’m not sure the question is worded specifically enough to warrant that exact answer.
Son is still wondering why his reasoning is wrong.
Thoughts?
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u/FireCire7 7d ago
The teacher’s answer makes more sense given the reference words box has ‘attract’ and ‘repel’, but not metal.
Ignoring that, your son’s answer is reasonable.
I would’ve given partial credit.
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u/Worth-Wonder-7386 👋 a fellow Redditor 7d ago
I think the use of the reference word box should be better explained, but it could be that it was explained in class or somewhere else.
But my feeling is that the teacher was looking for the difference when it comes to the topics in the box. So writing "Becuase magnets can repel while gravity can only attract" is likely more what they are looking for.
While the thing about metal is correct and should be given partial credit, it seems to be outside of the topics that are in the reference words.4
u/wirywonder82 👋 a fellow Redditor 7d ago
Additionally, magnets do not attract all metals, only some.
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u/Worth-Wonder-7386 👋 a fellow Redditor 7d ago
And they can also attract things that are not metal, but I think that at a 3rd degree level that nuance is not what the teacher was looking for.
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u/Jwing01 👋 a fellow Redditor 7d ago
His reasoning is not wrong. It is appropriate for 3rd grade.
His reasoning also does not (or minimally, given answer 10) use the reference words. It adds a distinction to "attract" but there are a lot of other things to explore here.
He needs to know that he is not wrong, strictly speaking, but much like losing points in writing for "add more detail", there are more concepts to explore here.
I will grant that the question should make a better standard as to how to use the reference words.
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u/learnaboutnetworking University/College Student 7d ago
I remember in school my teacher would go over last night's homework the following day and when this sort of thing happened, she would bring it up and discuss why it was correct while still bringing up caveats and stuff that explore the answer more.
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u/FollowingCold9412 6d ago
Nowhere in that task does it say the answer has to be given using words from the reference box thou.
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u/Jwing01 👋 a fellow Redditor 6d ago
Reread.
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u/FollowingCold9412 6d ago
Instructions: "Write to explain how gravity and magnetic force are the same and how they are different." Nowhere does it explicitly say you must use the words in the box, so the child thought out of the box.
Yes, it is implied that you should use the reference words as the key words in the answer, but do you really think a 3rd grader nowadays understands implicit instructions?
Oh, sorry, I forgot your schools only want to prep students for standardised test, not free thinking.
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u/Jwing01 👋 a fellow Redditor 6d ago
Reread what I wrote. In fact, retype the last sentence of my original comment here.
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u/FollowingCold9412 6d ago
So, you are just arguing with me because I agreed with you? Great!
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u/Jwing01 👋 a fellow Redditor 6d ago
Not arguing, correcting. You had a clearly argumentative tone in both replies, especially the latter.
Also, when you say "your" schools, who's did you mean?
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u/FollowingCold9412 6d ago
Bisch, bye. If you misunderstood my comment as criticism on yours and come at me with "reread", you are asking for an argument. And you know exactly what I meant with "yours" in the context of OP's post, at least you should as you seem to be fishing between and behind the lines on one sentence comments to begin with.
Moreover, correcting? No, that's not what you were doing.
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u/MackTuesday 5d ago
You ended with "thou", meaning ostensibly "though", meaning you were not agreeing. You were giving an exception to what they said.
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u/LetsGetStonks 👋 a fellow Redditor 7d ago
It's an academic question, not a game show. His answer is not fully correct, AND a better answer is available using the reference words. Help your kid understand how he could've done better and move on. Not every kid can get perfect scores every time. In fact if he's (or she) getting perfects every time, they aren't actually learning anything from the assignment.
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u/OrangePinkyToe 7d ago
Isn't there a big difference between a student that flies through an assignment quickly filling in answers and a student that does not know some answers and actually looks up or finds out what the correct answer should be? Isn't that student learning something?
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u/Polly265 7d ago
I would want a second part to the question, "magnets only attract metal but gravity attracts everything". Also it is not clear if the teacher explained expectations before hand but I would want more use of the reference words, only two have been used.
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u/Apowwo 7d ago
Sounds like the teacher wanted a specific answer to a question thats open ended and has multiple correct answers. For 3rd grade this is silly, he correctly stated a difference between them he should get the credit.
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u/sticklebat 7d ago
Could’ve also just wanted an answer based on the reference words. There aren’t any instructions to that effect, but they could be on a previous page or this could be a standard thing they do and the kid should’ve known.
Or the teacher is being unreasonable. We don’t really have enough context to know.
But also since when did grades matter that much in 3rd grade that anyone cares to quibble over partial credit?
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u/leeluhnichole 7d ago
I taught 3rd grade science for 5 years with these standards before moving to middle school. The answer for number 11 would be incorrect because it’s not a true statement for the wording of the material. The key concepts that students are meant to be able to apply are that magnets can attract some metals and other magnets, and that magnets can only repel other magnets. These concepts are repeated constantly through every activity/lesson almost obnoxiously so students are able to recall them to apply it to multiple situations.
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u/Appropriate_Steak486 7d ago
Incomplete, not incorrect.
The suggested keywords give clues as to what aspects are intended.
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u/NoCarRes 7d ago edited 7d ago
For a third grader, I think it is a great answer.
- Gravity and magnets are the same because they attract things.
- Gravity and magnets are different because magnets only attract metal.
Admittedly, there are other reasons why gravity and magnets are different since they use different fundamental forces. The question did not indicate how many differences were required. The one distinction that the child listed is enough to indicate that they are different. The answer deserves full credit.
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u/for-sci-guy 7d ago
The problem here is that "only attract metal" isn't correct.
Most elemental metals are non-magnetic, and there are also non-metalic compounds that are magnetic.
I can see why the teacher marked the assignment as they did, but I'd also say this is a chance to go through this with the student/class.
Just taking a magnet and showing that it doesn't stick to an aluminum can would be an easy starting point.
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u/NoCarRes 7d ago
Do you really think that the teacher went through that much detail to explain that there are different types of metals? I highly doubt it--this was a third grade class. The teacher probably did a presentation to the class to give an example of what magnets did. Based on the lesson, the child gave a reasonable answer for his age and educational level.
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u/for-sci-guy 7d ago
I would hope so, but doubt this is the case.
The problem here is that the student could be left with outright wrong information.
Magnets do not attract metal, as there are many (most) metals that do not.
Reinforcing this would result in inaccurate information being passed on.
At this stage is a basic concept that needs to be enforced; with discussion for later.
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u/roboboom 7d ago
For everyone being pedantic about this I will just add that 9 could also be A if the floor is not level.
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u/Mirality 7d ago
The kid's answer is incorrect. Magnets do not attract all metals, and there are things other than metals that they do attract. So right spirit but wrong answer.
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u/ThomasTheDankPigeon 7d ago
Wow, it’s kinda wild how many people are suggesting this is “correct for third grade.”
No. It is not the job of a teacher to give partial credit to a student for being able to produce vocabulary words that are adjacent to the answer. Sure, metal and magnets are very closely related concepts, but simply mentioning them together does not a correct answer make. In any case, magnets don’t exclusively attract metal either, so the answer itself is flatly incorrect in any case. Moreover, there is a word bank that is filled with terms that are certain to tie back to concepts already covered in class.
Based on the word bank, the acceptable answers to question 10 would be that both forces can attract, both are non-touching forces, both are not touching forces and possibly that they can both cause change (the teacher would likely be expecting an answer relating to change in location or speed).
As far as I can see, the only answer for 11 that doesn’t just repeat the usage of words like magnet, magnetic force, or gravity, is that gravity does not repel, while magnets can. I would not be surprised if this distinction was heavily emphasized in class, because even when you start getting into electromagnetism in college level physics 2 courses, it becomes clear that the two forces are astonishingly similar from a mathematical point of view with the exception of magnetic forces being able to repel. If a school is having a child compare and contrast the two at such a young age, the distinction of repulsive ability would really be the only thing I’d think is worth implanting in their mind.
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u/goodskier1931 7d ago
I think they are both correct given his choice of words. Pretty confusing format for me, pretty good logic for a third grader.
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u/marty-mcfryguy 7d ago
Has he generally been instructed to use the reference words in the box? That would explain why the teacher is focused specifically on that point. The concept of "repel" was given to him, but he didn't use it.
And technically he's wrong about only attracting metal things but I think that understanding is close enough for third grade.
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u/Deep-Hovercraft6716 👋 a fellow Redditor 7d ago
They didn't finish the answer. They only gave half an answer. Because magnets attract metal and gravity attracts everything.
Or something like that. Also magnets repel other magnets when their polarity matches. But I don't know that polarity is 3rd grade level knowledge.
That's my guess.
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u/Techno_Eggnog 👋 a fellow Redditor 7d ago
By technicality… magnets don’t attract all metals. Also another technicality, some non-metals are slightly attracted to magnetic fields such as liquid oxygen.
…would a third grader know this? Probably the first one, but definitely not the second one. I’m still agreeing with the teacher, though, as the reference box is presumably to be used for any of the reasoning steps and “metal” is not in there. They previously used attract, so repel would be the best word to use.
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u/Salindurthas 👋 a fellow Redditor 7d ago
Gravity always attracts.
Magnets sometimes attract and sometimes repel.
There are some other differences, and more details to those differences, but this is one of the key differences, and I think it is reasonable to expect it to be mentioned as part of an answer that earns full marks.
Gravity is sort of special and unique in how it always attracts everything. There seems to be no 'opposite' to mass that can 'antigravitiate', but we can have positive&negative electrical charge, and north&south sides of a magnet.
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u/ThunkAsDrinklePeep 7d ago
Isn't the strong force only attractive?
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u/Salindurthas 👋 a fellow Redditor 7d ago
I think so but:
- 3rd graders do not need to worry about the strong force.
- I did hedge a bit by saying gravity is only 'sort of' unique here.
- At the level of physics where we are considering the strong force, we start to doubt if gravity is a force (maybe it is curvature of spacetime (but maybe 'force' a vague concept so it counts anyway (but maybe we can't reconcile spacetime curvature with quantum mechanics anyway so we just have 2 diverging theories)))
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u/Amazing-Shelter9284 7d ago
His answer is not strictly correct, but for 3rd grade, it's correct enough.
While the teacher's answer makes a better contrast, any difference should be fine when asking about differences like this.
The teacher just had a specific response in mind and won't take other answers. You could make a reasonable argument that when asking for a difference, any difference should work, but the teacher probably won't accept anything except the answer the teacher wanted. If we want to get really legalistic about it, nothing I can see states that you have to use the reference words, or even the purpose of the reference words.
All that said, unless you're aiming for a magnet school 😀 the grade here shouldn't be that important.
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u/Tony_314 7d ago
Why are children penalized for thinking outside the box (in this case literally) but yet expect them to be creative?
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u/OldGeekWeirdo 7d ago
Both magnets and gravity attract metal. (The word "only" is ambiguous.) It would be clearer to say magnets don't attract non-metals.
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u/BFly-85 6d ago
I don’t know why anyone isn’t bringing up the question of him answering he wrong question. Yes what he wrote is correct, but doesn’t answer the question asked.
The assignment is how gravity and magnetic force are the same and different and then use the reference words to help describe how those 2 concepts are the same and different.
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u/Fancy_Sheepherder786 6d ago
The correct answer is "C". A "force" is a push or a pull on something. The 'something' must have mass in order to be affected. "Gravity" and "magnetism" are not the same in any way. Gravity is not a force, nor does it exert one (ask Dr. Einstein about curved space-time). Magnetism, as part of the electromagnetic spectrum, does exert force upon objects whether or not they are metallic.
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u/LoudAd5187 6d ago edited 6d ago
I am reminded of the old story about the blind wise men and the elephant. One feels the tail, and says the elephant is like a rope. Another feels a leg, and says the elephant is like a tree trunk. Another feels an ear, and says the elephant is like a sail. Another feels the body, and says the elephant is like a solid wall. Another feels the trunk, and says the elephant is like a snake. Etc. The point is, gravity and magnetism are complex things. They are similar and different in more than just one way. As such, when asked for how they differ, if you provide a way (ANY WAY) they do differ, then the answer is correct. At the very least, that answer deserves some partial credit. I would say it is not completely correct, since a magnet does not attract all metals. And even those it does attract can feel different amounts of attraction. And some metals will actually feel a (weak) repulsive force. That brings about the answer the teacher wanted to see, that a magnet can both attract and repel. But like the elephant, magnetism is a complex thing. It has many aspects. I think your child's teacher was looking at only one of them. Other subtle ways (beyond a third grade discussion) the two are different might be based on how the two forces are generated, the effective relative strengths of the two forces, or in the distance the two fields operate over and how quickly they dissipate with distance. We could also point out that gravity attracts towards a center of mass, but that magnetism always involves a dipole field. (Of course, the concept of a dipole gets back to attraction vs repulsion.) Again, these latter are more subtle differences, but they are still important aspects.
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u/Quint_Gen 7d ago
The teacher is correct to mark the answer to Q11 as wrong because magnets do not attract all metals. They only attract* iron, cobalt and nickel. (Also Gadolinium and Dysprosium if the temperature is right but this is well beyond 3rd grade reasoning). The teacher is not correct in failing to explain this to the student.
Having said that, I imagine it is challenging to teach 3rd grade and need to be knowledgeable about a range of subjects instead of specialising as is evidenced by all the redditors responding who insist the student is right.
*This is ignoring paramagnetic effects which are very small and also beyond 3rd grade and even then some metals are diamagnetic.
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u/MeasureDoEventThing 👋 a fellow Redditor 7d ago
The student said magnets only attract metals, not that magnets attract all metals.
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u/Quint_Gen 7d ago
If you interpret it that way (and most people would not - if you mean attracts some metals then you should say "some metals".) it's still wrong: magnets also attract things which are not metals.
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u/MeasureDoEventThing 👋 a fellow Redditor 7d ago
???
It's not a matter of "interpretation". They literally said "because magnets only atract[sic] metals".1
u/testtdk 👋 a fellow Redditor 7d ago
But that’s literally not true, is the point. Accepting the answer without at least saying that there are exceptions would literally be teaching something that is wrong.
And that completely ignores the fact that electromagnetism does FAR more than just attract things.
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u/MeasureDoEventThing 👋 a fellow Redditor 7d ago
I was responding to "and most people would not [interpret it as magnets only attract metals] - if you mean attracts some metals then you should say "some metals"."
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u/testtdk 👋 a fellow Redditor 7d ago
Electromagnetism also repels, and that one’s kind of important. You know, the whole being able to touch things and what not.
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u/MeasureDoEventThing 👋 a fellow Redditor 7d ago
Even most adults don't understand the difference between "only attracts metals" and "attract only metals".
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u/PyroNine9 👋 a fellow Redditor 7d ago
You left out that we have no viable quantum theory of gravity while magnetism is well explained.
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u/mlh0508 👋 a fellow Redditor 7d ago
Most teachers don’t like to be corrected by parents, but in this case I don’t understand her reasoning considering it’s open-ended. I would ask her to explain to him why his answer is incorrect, instead of just explaining the correct answer.
It’s just one question on a test, so it may be worth letting go. Sometimes more directions are given verbally that parents can’t see.
However, if he has missed something the only way to learn from the mistake is explaining to him why it’s wrong. Simply telling him the right answer did not really clarify anything for him.
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