General Right Triangle Word Problems

Howard is designing a chair swing ride. The swing ropes are 44 meters long, and in full swing, they tilt in an angle of 23°. Howard wants the chairs to be 3.5 meters above the ground in full swing.
 
How tall should the pole of the swing ride be?
Round your final answer to the nearest hundredth.
 
 
In order to do this problem, we have to apply the law of sines.
 
sin (67°) / x = sin (90°) / 4
x = 3.68
 
Where does 67° come from?
      If we draw a line perpendicular to the pole to the hypotenuse, we got a 90° angle. So, 180°- (90° + 23°) = 67°. 
 
We haven’t finished yet, we need to add x to 3.5 because they ask the entire length of the pole. 
3.68 m + 3.5 m = 7.18 m
 
*It is better to not round your answer during your calculation*
 
How tall should the pole of the swing ride be?
Round your final answer to the nearest hundredth.
 

VSEPR Model

Valence

Shell

Electron

Pair

Repulsion

VSEPR is a model used in Chemistry in order to predict a geometric shape of molecules based on the number of valence electrons. 

We can classify molecules into 7 main geometric shapes:

  • Linear                                      180°                    Non-Polar
  • Bent                                         104.5°                Polar
  • Trigonal Planar                   120°                    Non-Polar
  • Trigonal Pyramidal           107.3°                Polar
  • Tetrahedral                          109.5°                Non-Polar
  • Trigonal Bipyramidal       90°/ 120°         Non-Polar
  • Octahedral                           90°                      Non-Polar

Before figuring out any of those shapes, we need to draw Lewis Dot Diagram first. Let’s look at some examples:

 

Based on its Lewis Dot structure, we can classify HCN as Linear. 

As you can see above, Sulfur has 5 bonds. So, we would classify this as Trigonal Bipyramidal. 

Now, in this case, Sulfur has only 2 bonds. We would classify this as Bent. Why? HCN also has only 2 bonds but classified as Linear. That is because there are two extra pairs of electrons in the middle atom so those two pairs of electrons will push each of the two bonds down, creating an angle. 

Read & Write

On the 5th of October, it is the official launch of our school’s newspaper called the ‘Liger Edge’ !! There are a lot of incredible things happen in Liger and the only platforms we can use to share our stories are through Facebook and Instagram; furthermore, we can only write a few sentences. Therefore, we feel the need to create a school’s newspaper to spread stories of Liger in details. 

The newspaper is digital and we’ve established two websites for Khmer and English. We have 8 different categories: Features, Culture, Current Events, Stories of Change, A day in the Life, Opinion, Sports, and Caption this. We have 7 members in our team, all responsible as editors of each category. I am the editor in chief of Feature articles category.  So far, I’ve written three articles, though, not all are published. My first article talked about our new facilitators in this 2018-2019 school year. So, why don’t you check it out:

As We Fail – Features – Rika

Through writing these articles, I get a chance to enhance my writing skill and spur other students to share their voices through their writings. 

Our website has not yet been fully functioning, so sorry for this inconvenience. However, I hope my article above can act as a sneak peek to the incredible world of writings of our students.  

Wrapping up the history

In our literacy round 1 final assessment of the history of America. We were asked to do projects related to the history of America. 

In one of the texts that we’ve read is about the Great Depression. So, I decided to write a rhetorical analysis essay on Franklin Delano Roosevelt inaugural speech. Another work I did was to write an opinion article on Childish Gambino’s hit: ‘This is America’. To know more about what is my opinion of Gambino’s music video, go and check this out:

‘This is America’ Opinion article – Rika

Exponential Vs Linear Growth over time

Aril and Dita are wealthy Norwegian business owners who make monthly donations to international disaster relief.
 
 
  • Aril donated 150 Norwegian kroner (KR ) the first month and the cumulative number of Norwegian kroner she has donated increases by a factor of 2.5 each month. 
  • Dita donated 300 KR the first month and the cumulative number of Norwegian kroner she has donated increases by 400 KR each month.
They started making donations at the same time, and they both make their monthly donations at the beginning of each month.
 
What is the first month in which Aril’s cumulative donation exceeds Dita’s cumulative donation?
 
How do we go about solving this problem? First, let’s identify which statement describes exponential and which statement describes linear growth. 
 
Exponential growth is a growth whose rate is rapid in proportion to the function’s current value. Linear growth is a growth whose rate is constant over time. 
 
Based on the context, we can say that Aril’s donation is an exponential growth and can be model by an equation:
 
y = 150 * (2.5)^(x-1)
 
And Dita’s donation is a linear growth and can be modeled as:
 
y = 300 + 400(x-1)
 
Why (x-1)? Because in the first month which is x, Aril and Dita have already donated 150 KR and 300 KR respectively. Therefore, we have to subtract the first month to know the rate of the following months. 
 
Now, let’s figure out which month Aril’s donation exceeds Dita’s donation. Let’s think of it graphically.
 
We know that exponential growth started off slowly and will eventually outreach linear growth; therefore, we have to look for its intersection. 
 
The two lines intersect at 3.28, 1212.17. Therefore, we can conclude that at month 4, Aril’s donation will exceed Dita’s. 
 
What is the first month in which Aril’s cumulative donation exceeds Dita’s cumulative donation?
 
 

The Keystone Species

In AP biology class, we’ve just finished up our Unit 1: Ecology!!!! We’ve talked about important subunits including Biomes, Population Ecology, Population Growth, Community Ecology, Energy & Matter, and Conservation Ecology. 

In our last subunit, we had an assignment and that is to write a report about the conservation issue for a particular species/community/population in Cambodia. In that report, we have to describe its ecological significance, value to human communities, threats and the effects on biodiversity, current conservation actions, predictions, and our future recommendations. 

I chose to talk about Indochinese tigers; why? Well, Cambodia was known as a country with the second largest Indochinese tigers’ population in 1999. And guess what? Due to anthropogenic threats such as poaching of tigers and it preys, habitat fragmentation, and habitat degradation caused by massive deforestation, it is now pronounced functionally extinct. The last seen tiger was in Srepok Wildlife Sanctuary, Mondulkiri on November 2007. Inspired by the success of India, the government is working on tiger reintroduction to Cambodia specifically to the Eastern Plains Landscape. 

We as the human might think that tigers are dangerous and that they eat us, but we are solely responsible for the loss of this precious species. Why should tiger be reintroduced to Cambodia? How is it this important?

Read my full report here: 

Conservation In Cambodia

Writing, Writing

One the projects I joined for Round 1 of this school year is called Theatre Play. This is a year-long exploration in which we write our own play and perform it. So, in this first round, we’ve been working to shape our ideas for what we want our play to be about and write the script for the plays. Then, we’ll start recruiting actors and practice the performances in the following rounds. 

After various discussions, we’ve decided that our plays should be centered around the idea of relationships including the romantic relationship, peers, family, and social relationships. We then divided into four groups to take on different topics. My team is in charge of writing about peers relationship, but it hasn’t finished yet. 

The play will be in Khmer and perform it to Khmer audiences. Each of our plays has the message(s) that we want to convey. So stay tuned to our performances. 

Flames!!

After the incredible physics course last year, we’re now taking an introductory chemistry class with our new facilitator. 

We’re going through lessons such as scientific methods, isotopes, moles, ions, electron configuration, and emissions. 

Our latest lesson was on emission; we learned how atoms emitted energy to visible colors when it becomes excited.  So, let’s break it down. Throughout history, scientists had been debating whether lights act as waves or particles. But, in this unit, we’re learning when lights act as waves. Ok, what does that have to do with emissions? So, when some amount of energy hits an atom, some of its electrons become excited and jump to a higher energy orbital or excited state. Then, those excited electrons will release the energy as photons which are the visible colors and jumped back to its ground state. Those visible colors are release with different wavelengths that produce different colors. 

We also did a flame test lab on this lesson. It’s fun because..we get to wear those lab coats and it looks cool. Actually, there’s more than that. First of all, we lit up the Bunsen burner with lighters, then we put the different compounds of chloride and see observe the changes in the flame colors. Those compounds are barium, calcium, copper II, lithium, potassium, strontium, and an unknown #1. Then, we have to record all the data of different compounds and write a lab report for it.

My personal favorite is copper II:

This is the color produced when copper II reacted with flame

 

Are we ready…?

“How many hours you got for these projects?  What is your next class? Have you done any homework? What is the homework since I missed class today?” 

Voices of the senior are rising along the hallway trying to figure out what are they doing in their last 2 years of high school. 

Our schedule has just gone through tremendous changes; word to describes it would be ‘A LOT’. The education team is trying to shape our curriculum as similar to universities as possible to get us prepared. 

For our project-based learning, last year, we were picked to be on one certain project at a time. When we don’t like it, we can blame the facilitators. However, now, we have the right to choose what do we want to do that fits best with our passions and we get to experience a variety of things. So, if we don’t like it, it’s our fault. 

For me, it’s about science. I joined an advanced placement biology class or AP Biology which is like ‘the best’; I’m glad I joined. Then to maintain my literature skill, I’m a member of a school newspaper team called the Liger Edge and also participated in a Theater play that will be writing plays for performances. 

Building more on an established relationship with the International Labour Organization, I’m also a member of a team to help ILO implement soft skills training in Cambodia. On the other hand, I also joined a team that will be creating a podcast channel and talking about Cambodia to the rest of the world. 

It’s a lot, isn’t it? That’s not just me, that’s everyone else too. We have seminar hours with our facilitators and extra hours that we have to work independently on each of those projects. We were expected to spend 22 hours cumulatively for all of our projects a week. So, we have to use them wisely..!

It’s hard, but as we go along and think about it; we’re privileged to experience this during our time in high school!

 

University?

New school year 2018-19 kicked off with the SAT Bootcamp!!! yay… For the first two weeks after the summer break, two wonderful women, Amanda & Kim, volunteered to teach us how to take the SAT. 

“How to take the SAT”; as simple as that. 

But, things turned out pretty fun. Wait, but before the fun, we had to take the PSAT digitally on the first day of school; then we can start the boot camp. 

Clock ticking and two hours already passed; I didn’t realize the first class on the reading section with Amanda came to an end. So many words, so many strategies, so many readings… We went through the three main types of passages in the SAT: literary narrative, social science & natural science, and historical persuasive. Then we started to analyze 10 different types of questions and learned different strategies for each type of question!!!! 

I personally found historical persuasive passage is the hardest to understand because I’m not native American and it is antiquated English that no one uses nowadays.  

On the second week, our main focus shifted to writing and language section. Similar process: analyze questions types, learn the strategies, and practice it. 

“Keep the hardest passage for last and if you’re running of time, make an educated guess.” – Amanda. 

Shifted to the math section, Kim was here to teach us every shortcut we could take for math problems. We played games (math-related) and practiced lots of problems. We set goals for ourselves for how many questions we planned to get wrong (psychologically, it makes us feel less stress). 

“In real life, you have to do the proper steps, but for the SAT, it’s shortcut.” – Kim

The teachers spoke really fast and we got tons of homework every day which fried us for these first two weeks; however, this depicts what our lives are going to look like in universities. It’s hard for high schoolers, but we have to be prepared for everything because the graduation is in two years’ time. 

Despite all the work, we were able to create a strong bond with them. We’re so grateful for having you guys here. 

Image may contain: 40 people, including Amanda McCarther, people smiling, people sitting and outdoor