High School Students Memorization Versus Experimenting

[nivram4491]

My step daughter is spending her summer vacation attending a well known coaching college in Chiang Mai at my expense. She is going into Mor Hah (Year 11) next year.

I noticed one topic covered in her Physics course was density. I found a small brick with 3 holes through it, a tape measure and some kitchen scales and asked her to find the density.

She thought I was stark raving mad. Her first reaction was not to do it but with some coaxing and help she made a start.

Anyway she found the mass in grams, and together we found the volume of the brick and the volume of one cylindrical hole and made the assumption that the three holes were identical.

Everything was done in Excel so the calculations were easy to do. Our resulting density turned out to be 1.80 gram per cubic centimeter. A Google search showed that the density of a typical brick is 1.84 gram per cubic centimeter.

I was very pleased with our effort but it seemed to have little effect on my step daughter. Actual investigation of a physical property makes no sense to them. If the teacher tells them to memorize that the density of a brick is 1.84 gram per cubic centimeter and it then "means" something to them but to actually find the density by making measurements has no real meaning.

<snip>!

Edited March 12, 2012 by soundman
Debatable transliteration edited.

[naboo]

You should have found the volume by displacement.

[nivram4491]

You should have found the volume by displacement.

Could have not should have!

I wanted to find out if she could find the volume of a rectangular solid and the volume of a cylinder and if she would understand that you have to subtract out the volume of the three cylinders.

It would be a good idea to find the volume by displacement afterwards and then compare the two results.

My next project is to get a rock and a graduated measuring cup. In this case we will use displacement because there is no other way.

[Throatwobbler]

Science in Thailand is taught by rembering facts. Very little to do with experiments. If you are trying to teach you step daughter at grade 11 how to do experiments then I applaud you. However I feel you are far to late.

Agree with naboo though find the volume by displacement would have given you a far better answer, and would not have needed the extra maths and errors that would have occured.

[Throatwobbler]

Actually another good idea would be to find the volume by displavement and compare it to the volume that you worked out. See if your step daughter can see where the diference could come from. Errors in measurement etc..

[naboo]

You should have found the volume by displacement.

Could have not should have!

Sorry, you're correct, could have..I didn't mean for my post to be so curt, writing on a phone isn't easy so laziness creeps in!

Your step daughter will have memorized the formula for density. I would suggest looking at the units for density and seeing If she can see the relationship between units and formula. Play around with the formula finding mass given density and volume, then finding volume given mass and density. She may have done this. Then play around with units - ml and liters, grams any kilograms. You should be able to work out her level of maths and science from this, then take it from there.

I very much doubt she's been applying maths of volume to her work on density at school. Unfortunately the Thai system doesn't much look to achieve application of understanding.

[Diablo Bob]

Great idea, you've gone this far, how about throwing in Specific Gravity? The kitchen scales might be a problem though, you will need something with the capacity to weigh a container submerged in water.

Knowing the SpG you can then work the problem in reverse, "How many Kg of rock will you need for a specific volume"

[ThePunPun]

Great idea, you've gone this far, how about throwing in Specific Gravity? The kitchen scales might be a problem though, you will need something with the capacity to weigh a container submerged in water.

Knowing the SpG you can then work the problem in reverse, "How many Kg of rock will you need for a specific volume"

Unfortunately, for most Thais, [my opinion only] the test results , as to all of the above suggested methodologies, will mean nothing to most young people of that approximate age. The practical value of determining the weight, etc, is only to mean how far away from the police must you stand to throw a rock/brick of a certain weight.

On a more serious note, I would say that the Thai educational value is very low when compared against others in outside world levels. Sad but obviously true.

[uptheos]

I'm not quite sure if this is a post criticizing the Chiang Mai school's teaching methods, or telling us how bright some TV posters are?

Edited March 12, 2012 by uptheos

[Diablo Bob]

I'm not quite sure if this is a post criticizing the Chiang Mai school's teaching methods, or telling us how bright some TV posters are at physics?

Didn't learn it in Physics, learned it in Soil Mechanics (Geotechnical).

[uptheos]

I'm not quite sure if this is a post criticizing the Chiang Mai school's teaching methods, or telling us how bright some TV posters are at physics?

Didn't learn it in Physics, learned it in Soil Mechanics (Geotechnical).

Post adjusted accordingly.