# [S3] Lesson 30 : Thermal Physics Part 4 + (AM) Trigonometry Ratios + Metals I Updates/Debrief

[S3 Physics PMCians]

What we did in 2 hours:

On the 23rd, 25th and 26th Jul, the S3PH has come together to cover the following during our weekly lesson:

1) Complete on a new topic – Transfer of Thermal Energy

2) Discuss on two 4Qs quizzes

Always remember:

1) For metal, the main mechanism is Free Electron Diffusion mechanism while for non-metal it will be due to Molecular Vibration and collision.

2) Trapped air and Non-metal are poor conductors of thermal energy.

3) For convection, the hot fluid will expand in volume and become lesser dense and rise, while surrounding cooler and denser fluid sink. This will set up convection current.

4) For radiation, EMITTER will be used when T(object) > T(surrounding) while ABSORBER  will be used when T(object) < T(surrounding).

We will start on Mechanical Wave and EM wave this coming week! From this week on, we will be revising for the EOY examination. Kindly ensure that you have collected the TWO new books to be used from this week on.

Special Mention:

Should you have any questions, please feel free to send in your questions (and attempted workings) to 9100 1235. We will do our utmost to assist you in the questions. If you have any upcoming test or examination and would like to re-watch any of the past videos, do whats-app to 9100 1235 to inquire!!

Take care and Always with you,

The S3PH Tutors

(Mr Shane, Dr Li and Mr Gary)

[S3 Maths PMCians]

What we did in 2 hours:

This week, we covered Trigonometry Ratio. We learnt that from the ASTC diagram, we can find positive/negative trigonometry ratio depending on the quadrant(s). Considering special triangles, we see that some ratios can be expressed in exact surd forms.
We also discovered there are more trigonometry functions – secant, cosecant, and cotangent.

Please try the Takeaway Questions (Trigonometry Ratio) as homework before referring to the solutions.

Special Mention:

In the next chapter, we will look at Trigonometry Graphs and the characteristics of these graphs. For example in y = a sin bx + c , we will observe how the constants a, b, and affects the shape of the graph.

Your friendly PMC S3 Math tutors

[S3 Chemistry PMCians]

What we did in 2 hours:

We ended our Periodic Table chapter with a quick-fire quiz where we used big ideas of atomic radius on application questions involving concepts such as ionisation energy. We also noted the anomalies in the Periodic table (e.g. while atomic number increases, relative atomic mass may not increase in consecutive elements).

You may now complete your take home package on Periodic Table. Do clarify your doubts, if any, via whatsapp or during class this weekend!

Special Mention:

We will be taking a deep dive into the reactivity series of metals and how it can be used to justify displacement and acid/water reactions (recall our acronym again by this weekend!  ). Here’s an infographic of the reactivity series of metals:

Stay healthy, stay safe, see you this weekend!

Regards,

Mr Jacob