Danger of applying equation

[zoner]

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Just wanted to share with everyone.

Today, I ran into a question in TBR where it was related to torque. At first, the question seemed easy when you thought about just applying the torque equation. However, because the diagram that was shown on the question was upside down or something else, the answer actually utilized cos instead of sin. One of the answer choices did have sin as an option. I got it right because I ended up conceptually disputing myself regarding the usage of sin and went with cos purely by logic driven by the diagram. However, I could see how easily one could just apply the equation pulled out from memory and get the question wrong.

This brings me to think, maybe it is actually more disadvantageous to memorize the equation since it makes you want to apply it without thinking about the concept behind it.

Anyone else have similar experiences?

 

[NickNaylor]

Just wanted to share with everyone.

Today, I ran into a question in TBR where it was related to torque. At first, the question seemed easy when you thought about just applying the torque equation. However, because the diagram that was shown on the question was upside down or something else, the answer actually utilized cos instead of sin. One of the answer choices did have sin as an option. I got it right because I ended up conceptually disputing myself regarding the usage of sin and went with cos purely by logic driven by the diagram. However, I could see how easily one could just apply the equation pulled out from memory and get the question wrong.

This brings me to think, maybe it is actually more disadvantageous to memorize the equation since it makes you want to apply it without thinking about the concept behind it.

Anyone else have similar experiences?

Duh. The equations can only get you so far.

 

[zoner]

well, this is making me think, why bother spend time memorizing equations on flashcards or what not. If they stick they stick, if not, then don't bother maybe excpet for kinematics.

 

[ilovemcat]

Just wanted to share with everyone.

Today, I ran into a question in TBR where it was related to torque. At first, the question seemed easy when you thought about just applying the torque equation. However, because the diagram that was shown on the question was upside down or something else, the answer actually utilized cos instead of sin. One of the answer choices did have sin as an option. I got it right because I ended up conceptually disputing myself regarding the usage of sin and went with cos purely by logic driven by the diagram. However, I could see how easily one could just apply the equation pulled out from memory and get the question wrong.

This brings me to think, maybe it is actually more disadvantageous to memorize the equation since it makes you want to apply it without thinking about the concept behind it.

Anyone else have similar experiences?

Well if you actually understood what "Torque" is - the whole sin(theta) part of the equation would have more meaning. The equation is still useful ... you just have to realize how it works.

 

[ModernAlchemist]

well, this is making me think, why bother spend time memorizing equations on flashcards or what not. If they stick they stick, if not, then don't bother maybe excpet for kinematics.

Equations are easy ways to relate general trends and variables in science. Using an equation is similar to saying all eukaryotes are multicellular. That's not true, but generalizing is easier than learning every specific case. Since the MCAT is expanding your understanding of the topic, they test specific cases and have you apply the equations with the new information in mind. Berkeley Review books applies this idea to most topics in their physics review.

 

[Rabolisk]

Equations are always correct, if you apply them correctly. For example, you have to realize that τ = rFsinθ comes from τ = r×F (all vectors), and you have to consequently know what each variable refers to. The danger in memorizing equations is that it can fool you into thinking that that's all you need to know.

Using an equation is similar to saying all eukaryotes are multicellular.

I don't know if that's the best analogy. Equations are absolutely correct when they are applied in correct situations, whereas eukaryotes always being multicellular is just simply not true. After all, the defining characteristic of a eukaryote is that it has membrane-bound structures like the nucleus that prokaryotes lack.

 

[ModernAlchemist]

Equations are always correct, if you apply them correctly. For example, you have to realize that τ = rFsinθ comes from τ = r×F (all vectors), and you have to consequently know what each variable refers to. The danger in memorizing equations is that it can fool you into thinking that that's all you need to know.



I don't know if that's the best analogy. Equations are absolutely correct when they are applied in correct situations, whereas eukaryotes always being multicellular is just simply not true. After all, the defining characteristic of a eukaryote is that it has membrane-bound structures like the nucleus that prokaryotes lack.

Haha I knew someone smart would call me out on that. I sat there for like 2 minutes thinking of a good analogy and settled for that one. You're right. It's not the best, but I was trying to get across the idea that equations are a way to relate observable trends that were concluded from previous experiments. Maybe I should have waited until you or BRTeach came along...