Lower Secondary Science

[mum_sugoku]

Dr.Daniel:

njcstudent:

Hi, I am an IP student in Sec 1. Can anyone please recommend any good reference books and assessment books?

I had an njc student in Sec1 last year and they were not following a standard syllabus and were doing very hard material early on. One of their modules was called \"basic atmosphere\".
Best advice I can give is to build up your basic physics and chemistry understanding. The textbook Interactive Science for Inquiring Minds is not bad. Try to understand measurement, density, speed and then go through elements and compounds and atoms and molecules.
You will probably need a higher level book for O-Level, such as Physics Insights and Chemistry Insights as a reference for harder topics.
On assessments, The red book Lower Secondary Science by GS Cheng is good.

My DS is also currently a year 1 student in an IP school. Agree that their science is rather tough. Take my DS for instance, while he used to score good grades in science in his pri school, he has managed to get only 'C's and 'D's for his science assessment so far ..

[keithjes]

nono81:

Hi Parents,

My friend and I (both female in late 20s) provide the tuition three sciences separately, is like offering one-stop tuition service for secondary science to meet the demands of modular science. I tutor chem and bio while my friend is tutoring physics. We are very experienced. If you are interested, do pm me. Thanks.

My daughter in Sec 3 is looking for Bilo and Chem tutor, can I have your contact pls.

[Verysuperkiasu]

What’s the water concentration level in a typical carrot tissue?

[Verysuperkiasu]

http://i42.tinypic.com/30u6zpy.jpg\">


DS requests me to put this up

In order to know which direction the air bubble move along the capillary tube, he needs to know the water concentration in a carrot tissue. Or do u have any suggested answer?

[Dr.033430Daniel]

Verysuperkiasu:

What's the water concentration level in a typical carrot tissue?

Less than distilled water.

So the distilled water moves into the carrot tissue by osmosis.

[Verysuperkiasu]

Dr.Daniel:

Verysuperkiasu:

What's the water concentration level in a typical carrot tissue?

Less than distilled water.

So the distilled water moves into the carrot tissue by osmosis.

Got it...thanx!

[Gems]

Anyone can help?


1. Pressure exerted by a force of 5N the tip of a knife is 360kPa. What is the area of the tip of knife in cm2?

2.A car moves along a smooth road with its engine exerting a constant force. What change will occur to the car?
a. Its speed will increase.
b. Its acceleration will increase.
c. Its mass will increase.
d. Its direction of movement will change.

Thank you.

[Dr.033430Daniel]

Gems:

Anyone can help?


1. Pressure exerted by a force of 5N the tip of a knife is 360kPa. What is the area of the tip of knife in cm2?

Pressure = Force/Area
Pascals = N/square meter
360,000 Pa = 5N/Area
Area = 1.39 X 10-5 square meters X 10,000 square cm per square meter
= 0.139 cm2

[Dr.033430Daniel]

Gems:

Anyone can help?


2.A car moves along a smooth road with its engine exerting a constant force. What change will occur to the car?
a. Its speed will increase.
b. Its acceleration will increase.
c. Its mass will increase.
d. Its direction of movement will change.

A is the best choice, although there are issues with the question.

\"smooth road\" I interpret as meaning no friction . Usually \"smooth\" means no friction, while \"rough\" indicates friction.

The only possible interpretation of the question given the MCQ choices is that there is a constant driving force and no friction. So that being the case there will be constant acceleration and an increase in speed.

But there is a problem with the question. It is friction between the wheels and the road that allows the driving force to move the car forward. (standard O-Level question by the way). If a car has its wheels on an oil slick and there is no friction, the wheels cannot grab onto the road. The wheels will just turn and there will be no driving force behind the car.

Also, the main contribution to friction opposing the motion in the case of a car is friction with the air.

So a clearer question would be \"a block is pushed on a smooth surface by a constant force.......\"

no issue with wheels, and air friction is minimal just pushing a block along a surface (low speed implied compared to a car)

[Gems]

Sorry, we still don’t understand the 1st question. How to derive at 1.39? Multiply out could not get the area too. Thanks.