# [S3] Lesson 21 (25-31 May) Updates/Debrief

[S3 Physics PMCians]

What we did in 2 hours (PMC LIVE):

Over the weekend of 23 and 24th of May, we completed the Turning Effect of Forces MYE Revision.

Do remember that to solve the Rotational Equilibrium,

1. locate the pivot,

2. identify all the forces and the perpendicular distance,

3. classify all the forces to CW or ACW.

And as for stability related questions, do remember to include

1. the line of action of W, and

2. restores or topples.

In our tutorial, we will be discussing on a new topic, ‘Thin Lens’. Do logon to the PMC Teachable Website for any updates of notes or handouts.

Special Mention:

Of course, should you have any queries , feel free to contact the tutors @ 9100 1235 (PMC HQ). We will always be there to guide you in your understanding.

The S3PH Tutors

(Mr Wong, Dr Li and Mr Gary)

[S3 Maths PMCians]

What we did in 2 hours (PMC LIVE):

We started on Binomial Expansion this week. We found that the formula to expand (a+b)n has a pattern in it.

While going through different question types in the booklet, we learnt how to:

1) rewrite (a+b)n to (b+a)n to have the expansion in ascending/descending powers of x.

2) do trinomial expansion in an efficient way

You may start trying some of the Takeaway Questions (Binomial theorem):

• Page 157, Question 1 and 2

Solution will be uploaded next week.

Please click the link here for the solutions to the sections below:

• Solutions to Live Chat Challenge (Binomial Theorem)

Special Mention:

In our next LIVE, we will continue the chapter on Binomial Theorem, understanding the general term in the expansion. We discovered that our calculator can do nCr, by the way, do you know that nCr has a formula too? We will find out more in LIVE and see what are the questions that need this formula.

Your friendly PMC S3 Math tutors

[S3 Chemistry PMCians]

What we did in 2 hours (PMC LIVE):

We have kickstarted the first of a series of two mid year revision package with the best top school and O level questions. Through this series of revision, you will be introduced to accurate question analysis and efficient problem solving skills.

This is great opportunity to consolidate the chapters we have learnt over the two terms to build a strong foundation for the second half of the year and prepare for class quizzes many of you are expecting when school reopens.

Special Mention:

Here’s a quick infographic on polyatomic ions, many of which you should recall and remember their charges well!

Stay healthy, stay safe, see you this weekend!

Regards,

Mr Jacob

Home-Based-Learning (HBL)

1) PMC Lecture webcast (www.pmcdigital.sg)