I know it is exam time, but there are two things regarding scientific experiments that parents should make sure their children understand.


1.\tThe highest grade on a practical assessment may be given to the student that makes the fewest mistakes, however the exact opposite is true in both scientific research and in life. Thomas Edison made a great many failed attempts at inventing the light bulb. But he learned from his mistakes and he was persistent. It was these two qualities that lead to his being one of the greatest inventors of all time. And in life also, we all make mistakes. But the ability to admit them, learn from them, grow from them, and move on, is what builds our character.

2.\tMost of the important discoveries in science have come from experiments that DID NOT turn out as planned. JJ Thomson saw charged particles (electrons) coming out of different metals, from copper to gold to lead. But these particles were identical. What a shocker! How could gold and lead be made up of identical things! So you don’t do an experiment in science to regurgitate a pre-determined result. You do an experiment with an open mind to see what is going to happen. Yes, it is good to be disciplined with good technique, and the practicals can be good for that. But the mindset of being open to recognize and pursue the unexpected is the mark of a good scientist. When I did experiments in my classes, it was the students who played around a bit and discovered something outside of the normal procedure of the experiment and asked – why does this happen? – they learned the most.

Sorry to go all philosophical at exam time, but these are some things to consider as important lessons for students to absorb when the pressure of exams is not imminent. Do what you need to do to get the best grade on the SPA, and learn how to be methodical from it. But don’t forget the other qualities of how to be a good scientist!

Hi, Yes I am still around. I sent you a note by email. I am making a lot of resources available online now.

jadee_ong:

Hi, I'm a sec 2 student and idk what to choose for my science subjects for double science. Only Phys/Chem and Bio/Chem allowed in my school. My bio not so good but I prefer this. My Physics is better but I don't like it as much. Pls help me! Thanks

Bio is good preparation for the medical and pharmaceutical industry or if you like working with animals or plants. Take bio if finding a cure to cancer appeals to you. Physics is good if you are more inclined toward engineering or electronic devices. Take physics if building robots or inventing the next iPhone appeals to you.

Balancing what you are good at vs what you like is a tough challenge.

buttercreem:

Please help with this question. Thank you.


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These are the kinds of questions we go over with students during our September Holiday Program for End of Year Exam Revision (including IP) and O'Level Physics. I'm doing a lot of these problems with Sec 3 and Sec 4 students as well in our regular Physics tuition classes.

The answer is in two parts. For the first part, use a kinematics equation to solve for the initial velocity. We strongly recommend memorizing the 4 equations used for kinematics, as this is the fastest way of solving these kinds of problems.

For the second part, set the calculated kinetic energy = 95% of the actual kinetic energy. This needs to be done carefully. This little step at the end comes up in a lot of places in physics where efficiency is involved and it is important to think about the answer at the end. The actual initial velocity must be higher than the calculated initial velocity because energy was lost along the way.

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Newtandcucumber:

Hi, can anyone who is familiar with the Singaporean Physics O level, advise if the new Physics Higher GCSE, done here in the UK, is easier or harder than your o level. Please look at the Specimen Higher Paper only. The URL is below:


http://www.aqa.org.uk/subjects/science/ ... -resources

The topics covered in the Higher GCSE paper are in some cases different than what is found on the Singapore O'Level. So if you are practicing the Singapore O'Level to prepare for this paper it will be inadequate preparation. One example is the question on the expansion of the Universe, which is not covered in the O'Level. Another example is nuclear physics and the radioactive decay questions. Also, most of the questions in the Higher GCSE paper are asking students to explain their reasoning and it is testing the ability of students to draw on their general knowledge to answer the questions. It contains questions of a different style than commonly seen on the Singapore O'Level (although the O'Level is trending in this direction in the last couple years). This UK paper is more in the style of the IB exam, although not as hard as the IB exam. So practicing the Singapore O'Level is OK for some of your preparation, because there is overlap, but try to get a hold of UK papers more in the style of this exam to complete your preparation.

Overall I like this test. We use some questions of this style in our classes to prepare Singapore students for the O'Level because as I mentioned, the O'Level is trending in this direction. It also helps Singapore students to get exposed to different styles of questions and makes them more flexible as exam takers. But sometimes it takes a lot of explanation to the students to help them with the thought processes needed to arrive at the answers.

cftan:

The book 'Longman 1001 MCQ' is meant more for O level rather than lower sec?

If you look closely at that book, the questions are labelled with difficulty levels 1-3 (symbolized by fingers on a hand). Difficulty level 1 can be used for lower secondary. A student can try level 1 questions first, then check their answers, then proceed to level 2. Difficulty level 3 would be more challenging upper secondary style questions. These however would be appropriate for Sec2 students in IP classes. This book is good for checking the student's knowledge of basic facts and concepts and the ability to do short calculations using the correct formulas.

Coming up with the right level of difficulty for practice worksheets for lower secondary takes a bit of investigation as to the class that the student is in. Some classes focus on a few topics and do significant amounts of O'Level difficulty. Other teachers like to cover more topics but at less depth. And then there are the ones covering a lot of topics also at a lot of depth. But aside from the MCQ's, help with answering structured questions is very important. I spend a lot of time in tuition class on structured answers because the questions in the schools are trending harder in the last few years in lower secondary. There is a lot of testing on being able to explain the cause and effect relationships in science. This requires clear understanding of the concepts first. Then second is the ability to express thoughts in writing using the accurate words and terminology. This just take a lot of practice and guidance. But this is what is separating the A's from the B's in a lot of cases now.

For Science, my experience in tutoring for 6 years is that students are better off getting a good start, rather than trying to catch up. For understanding science concepts, it is important for students to get on the right track ASAP in their ability to think scientifically, rather than the standard practice of dumping info into short term memory. Developing good thinking skills will make understanding the concepts and knowing how to apply them to the questions a lot easier. A good tutor or center with the know-how can help students start on the right track.


An analogy would be if you want to learn how to play tennis, the first order of business is to get a really good coach so that your swing has proper form. You could go out and spend many hours just playing but you would be developing bad habits. The same is true for studying science. There is a way to go about studying science subjects that leads to long term success and then there are ways that lead to mediocrity and not really building understanding as you go.
The longer you play tennis with a bad swing, the harder it can be to unlearn bad habits. And the longer you try to study science the wrong way, the tougher and more frustrating it can become. In the meantime, the students that got on the right track in the beginning find it easier to progress through the year, and from one level to the next, because the fundamental skills are there.

Once a student has those fundamental thinking skills in place, there are many times where I have been surprised at how far they can go! I see students every year where my first impression is they are really going to struggle. But once the light bulb went on in their heads as to how to properly approach science subjects, they were regularly getting A’s!

Blanja85:

Dear Dr Daniel,

I am interested to enroll my son who is going sec1 next year. Please provide me the information's or pm me.
Thz

OK - sent you a PM. Our website is in my profile here. You can see it by clicking on my name.

Just one piece of advice for parents with students going into Sec 1 Science: Make sure they learn the metric system ASAP. They should know how many millimeters are in a centimeter, and the other prefixes such as kilo, Mega, Giga, micro and nano. The difference in preparing for the first physics test will be huge for those kids who already know the metric system vs those who still struggle with it.

What I noticed this year was that a few more primary schools are picking up on teaching the metric system now. During our holiday program there was a big gap between kids who had been taught the metric system in primary and those who had not (still the majority have not). We closed that gap for a lot of students, so for those who were new to it, they now have the advanced knowledge going into Sec 1. The ones that had already learned it were challenged with tougher questions. It is not a hard topic, certainly much easier that a lot of those P6 model questions, but it is very important for Sec 1 Science preparation. We will be reviewing it again in January.

Here is an answer to Mental of Steel's question. I saw this type of question from no less than 5 different schools on either CA1 or SA1 for Sec 3 in 2015 and I expect it to be a popular exam question for Sec 3 in 2016. We have these kinds of questions in our tuition center worksheets because we are constantly updating with the recent school questions.


Here is the question:
http://physicsandcalculus.com/wp-content/uploads/2015/11/scale-diagram-question.jpg\">

The most important thing to realize about this question is that you cannot use the original drawing for a scale diagram. The reason why is that the 500N force is in a rope that is longer than the rope containing the 866N force. That's possible by the way. Just because I have a shorter rope doesn't mean that the tension, or the force within that rope, has to be less. It could be more.

So we must redraw the problem and we redraw using the tip to tail method of vector addition. You use a protractor. Take a scale of say 1cm = 100N. First, draw the 866N force being 8.7 cm long with a ruler and use a protractor to draw it at the correct angle. Then start at the tip of the 866N force, draw a horizontal line (dotted red line), measure the correct angle and draw the 500N force as 5.0 cm. Then you draw the resultant force in black as shown. Measure it with your ruler and it should come out to about 10.0 cm. This is 1000N according to our scale. That resultant upward force is also equal to the weight downward. The resultant force is acting directly opposite the weight, so there is no angle with respect to the vertical, it is exactly vertical.

http://physicsandcalculus.com/wp-content/uploads/2015/11/answer1.jpg\">

So the answers are:
Scale: 1cm = 100N
Magnitude of Resultant Force: 1000N
Direction of Resultant Force: Exactly Vertical
Weight: 1000N

So then you can verify your answer with trigonometry. There are two ways to verify the answer. One using the trig components and the second if you can see the resultant is the hypotenuse of a right triangle. So for those of us who may not have the artistic skills of Leonardo Da Vinci, we can make sure the darn drawing comes out right by doing the side calculation. So your resultant vector should come out to about 10.0 cm.

For those asking questions about classes, just PM me. I do not advertise in the forum posts. I just try to post interesting and helpful information.


But what you are all asking are good questions. Short experiements and hands on things are great to work into science lessons in the context of the syllabus. I like doing things that relate to the syllabus, so its not just about hands on. It is about how the hands on activities relate to what students are supposed to learn.

We were taking a break during our 3 hour Sec 1 Science (Chemistry) Holiday Class. We were drinking milo, so we decided to build a molecule that is in cocoa. The molecule pictured here is called Theobromine (which is a funny name because the element Bromine is not in the molecule). It is found in chocolate. We estimated more than a billion times a billion of these molecules exist in one cup of milo. The colors that represent the different atoms are: Black: Carbon, Red: Nitrogen, Yellow: Oxygen and White: Hydrogen. The chemical formula is C7H8N4O2. This molecule is very similar to caffeine and is also a mild stimulant. In any case this was a good opportunity to study the difference between atoms and molecules, and some details as to how atoms bond together in a molecule including double bonds and single bonds. Notice each carbon atom has 4 bonds, each nitrogen 3, each oxygen 2 and each hydrogen just one. We go over the Chemistry logic for this that we teach the students from the Periodic Table of the Elements.
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