Lower Secondary Science

[ChewingPencilLine]

Herbie:

I hv one physics qn, can someone help to solve this qn.

A student wished to determine the density of iron. He obtained several pieces of iron of irregular shapes and measure their masses. He then obtained theircindividual volumes using the method of displacement.
a. A using the readings obtained, he plotted a graph of volume V against mass m. Sketch the shape of the graph obtained in the axes provoded. Explain yr answer.y axis is v/m3 and x axis is m/g.
b. How would he obtain the density fr the plotted graph?

Density = mass / volume = m / V
Plotting a graph of V against mass m means making V the subject of the equation:
V = m / D

Therefore, the graph is a straight-line linear graph with 1/D as its gradient.
In order to obtain the density, find the reciprocal of the gradient of the graph.

[moomoo138]

Hi


Need some advice pls. I would like to find out between the following textbooks by Marshall Cavendish, which is a better guide:
1) Discover Physics - GCE ‘O’ Lvl Science
2) Physics Matters - GCE ‘O’ lvl

Thanks!

[superkiasume]

moomoo138:

Hi


Need some advice pls. I would like to find out between the following textbooks by Marshall Cavendish, which is a better guide:
1) Discover Physics - GCE 'O' Lvl Science
2) Physics Matters - GCE 'O' lvl

Thanks!

The textbooks are used by my two sons, who are in different schools and levels. I feel that the contents are quite similar. Both are quite good and useful.

By the way, I have also bought the Perfect Guidebooks, also by Marshall Cavendish. I was under the impression that the books are good, since they are written by the same company that published the textbooks. However, I was mistaken. The points are very repetitive, nothing different from the textbooks. My boys do not find them useful at all.

[moomoo138]

Hi Superkiasume


Tks so much for your advice… really appreciate it… In that case, I’ll try to get either one then… Tks again… : )

[BBEwee]

superkiasume:

BBEwee:

Is there any good Secondary science guide books to to recommend?

I personally find the following books useful:

1) Longman 1001 MCQs (http://www.pearson.sg/cos/o.x?c=%2Fpearson%2Flocallib&ptid=176&pg=1&sort=&subj=Physics+&level=&kw=mcq&type=title&ipp=20)

2) Smashing Exams (http://smashingexams.com.sg/)

The Marshall Cavendish Science guidebooks aren't too good though, in my opinion. I don't find the materials inside any different from the textbooks.

Thank you so much for your help.
Will take a look at the 2 books that you recommend .

[SWEETMOM9]

BBEwee:

superkiasume:

[quote=\"BBEwee\"]Is there any good Secondary science guide books to to recommend?

Hi!
I recently purchased Smashing exams vol 1and 2 for lower sec n I find it useful.
I personally find the following books useful:

1) Longman 1001 MCQs (http://www.pearson.sg/cos/o.x?c=%2Fpearson%2Flocallib&ptid=176&pg=1&sort=&subj=Physics+&level=&kw=mcq&type=title&ipp=20)

2) Smashing Exams (http://smashingexams.com.sg/)

The Marshall Cavendish Science guidebooks aren't too good though, in my opinion. I don't find the materials inside any different from the textbooks.

Thank you so much for your help.
Will take a look at the 2 books that you recommend .[/quote]

[pchong]

[1) Longman 1001 MCQs (http://www.pearson.sg/cos/o.x?c=%2Fpearson%2Flocallib&ptid=176&pg=1&sort=&subj=Physics+&level=&kw=mcq&type=title&ipp=20)


2) Smashing Exams (http://smashingexams.com.sg/)

The Marshall Cavendish Science guidebooks aren't too good though, in my opinion. I don't find the materials inside any different from the textbooks.[/quote]


Thank you so much for your help.
Will take a look at the 2 books that you recommend .[/quote][/quote]
Thanks for the sharing

[archie2]

physic Question


A block resting on a smooth horizontal floor is being pushed by a constant horizontal force.
the answer states that if the velocity at 1s is v, then the velocity at 2s will be 2v and the velocity at 3s will be 3v.
can someone explain why the velocity change from v to 2v and 3v ?
thank you
rgds

[Oldschool]

archie2:

physic Question


A block resting on a smooth horizontal floor is being pushed by a constant horizontal force.
the answer states that if the velocity at 1s is v, then the velocity at 2s will be 2v and the velocity at 3s will be 3v.
can someone explain why the velocity change from v to 2v and 3v ?
thank you
rgds

Hi,

This has to do with the understanding of Newton's 2nd law of motion, which states that,

\"The change in velocity (acceleration) with which an object moves is directly proportional to the magnitude of the force applied to the object and inversely proportional to the mass of the object.\"

Mathematically, Force = mass x acceleration

and Acceleration = (Final Velocity - Initial Velocity) / time interval

So for a constant force, the change in velocity or acceleration is also constant.

Therefore, resulted in the above statement \" if the velocity at 1s is v, then the velocity at 2s will be 2v and the velocity at 3s will be 3v\"

This can be illustrated as below,

http://i43.tinypic.com/312hj6d.jpg\">

Regards

[Vivian22]

Hi,


I have two Physics question to ask. Can someone please help? Thanks in advance!
http://i41.tinypic.com/ilf4wh.png\">
http://i41.tinypic.com/9ier77.png\">