## FTC Kick-Off Event Planning

Each year, FIRST Tech Challenge reveals the game for the new season on either the first of the second Saturday of September. This past year, the kick-off event was held on Saturday, 10-September-2017.

This year, our region held a kick-off event at University of Texas at Dallas in Hoblitzelle Hall in Cecil Auditorium. That lecture hall is able to accommodate a few hundred, but was at capacity. Some teams had to be turned away to ahead-of-time to other events that had to be organized to handle overflow.

For the 2017-2018 kick-off event, Ferris High School will be opening its doors to host teams from across the North Texas region!

The plan would be to house teams, three covered game floors, and the emcee in the main gymnasium during the kick-off event.

Depending on how many teams attend, we may also have 3 additional game floors in the auxiliary gymnasium.

When we have hosted FTC events in the 2016/2017 year, the main gymnasium was where the single game floor was placed and spectators were seated in the stands. The auxiliary gymnasium was used for the team pit areas and practice floor(s).

## Panorama Fun

Had some extra time in my computer lab today to clean and put some materials on the walls finally. Also gave me an excuse to play with the panoramic camera apps I have on my phone. ðŸ˜œ

## Projectile Motion Worksheet #2

My Principles of Technology class is continuing to work on the preparations for the projectile motion project of launching a water balloon at me from 40 yards away.

Today, we analyzed how to calculate the maximum height and maximum range of a projectile.

I first showed them the formulas and we pulled apart the variables:

We then discussed that the mass of the object does NOT appear as any of the variables. We discussed why this is and then watched the following video:

Afterward, we started to work on the problems in the following online worksheet.

Projectile Motion Worksheet

The first 5 questions are short answer and will vary by student. The answers to the last 15 questions are providedÂ at the link below:

Projectile Motion Worksheet Solutions

Up next, we will analyze dragÂ coefficients and the impact of air/wind resistance on the flight path of the balloon.

We’ll then move into designing a launch apparatus that can launch the projectile at the correct angle and velocity.

Finally, we’ll move to testing. Fortunately, for this project, no fires!

## Flipping Stacks

We are now going to look at how to flip a stack. As was discussed previously, a stack is an ideal method for holding items in a queue such as an incoming call center.

Let’s say the following calls come into a call center. They are time-stamped for reference.

Call 5 – (469)382-1285 – 2017-02-13 / 08:02:57
Call 4 – (682)552-3948 – 2017-02-13 / 08:02:45
Call 3 – (214)233-0495 – 2017-02-13 / 08:01:55
Call 2 – (817)927-3849 – 2017-02-13 / 08:01:22
Call 1 – (972)828-1847 – 2017-02-13 / 08:01:13

In this case, the call that has been placed on hold the longest is “Call 1”, which came in at 8:01:13. However, recall that in a stack I can only interact with the item on the TOP of the stack. In this case, that is “Call 5”.

So, we are going to create a system that “flips” this stack over, pulls the new top item off and then returns to stack to its original order so additional calls can go in the place they should.

So, assuming that we have a stack already created for the numbers, we will need to create an empty temporary stack to hold the items. As we move the items over, the temporary stack will look like the following:

Call 1 – (972)828-1847 – 2017-02-13 / 08:01:13
Call 2 – (817)927-3849 – 2017-02-13 / 08:01:22
Call 3 – (214)233-0495 – 2017-02-13 / 08:01:55
Call 4 – (682)552-3948 – 2017-02-13 / 08:02:45
Call 5 – (469)382-1285 – 2017-02-13 / 08:02:57

As you can now see, “Call 1” is at the top of the stack and could be routed to the next available individual. However, if another new call were to come in, the stack would look like the following:

Call 6Â – (512)231-1933 – 2017-02-13 / 08:03:19
Call 2 – (817)927-3849 – 2017-02-13 / 08:01:22
Call 3 – (214)233-0495 – 2017-02-13 / 08:01:55
Call 4 – (682)552-3948 – 2017-02-13 / 08:02:45
Call 5 – (469)382-1285 – 2017-02-13 / 08:02:57

To avoid our call queue getting mixed-up, immediately following the retrieval of the top item on the stack, we need to move the items from the temporary stack back to the original stack as follows:

Call 5 – (469)382-1285 – 2017-02-13 / 08:02:57
Call 4 – (682)552-3948 – 2017-02-13 / 08:02:45
Call 3 – (214)233-0495 – 2017-02-13 / 08:01:55
Call 2 – (817)927-3849 – 2017-02-13 / 08:01:22

Now, when “Call 6” comes in, it will go where it is supposed to go (following “Call 5”).

Let’s analyze the code for this problem.

```//Program Name: Flipped Stacks
//Programmer Name: Eric Evans, M.Ed.
//Programmer Organization: Ferris High School
//Program Date: Spring 2017
import java.util.*;
public class flippedstacks {
public static void main(String args[]){
int count, myStackSize, myTempStackSize;
Stack myStack = new Stack();
for (count = 1; count <=10; count++){
myStack.push(count);
}
myStackSize = myStack.size();
Stack myTempStack = new Stack();
for (count = 1; count <=myStackSize; count++){
myTempStack.push(myStack.pop());
}
System.out.println("Current Caller is " + myTempStack.pop());
myTempStackSize = myTempStack.size();
for (count = 1; count <=myTempStackSize; count++){
myStack.push(myTempStack.pop());
}
}
}```

Lines 1 – 4 are the general header information. Lines 5 – 7 are the imports and creation of the class and main object.

Line 8 creates 3 uninitialized integer variables: count, myStackSize, and myTempStackSize.

Line 9 creates a new empty stack named “myStack”.

Lines 10 – 12 push content into the “myStack” stack. It pushes numbers 1, 2, 3, 4, 5, 6, 7, 8, 9, & 10 into the stack.

Line 13 initializes the value of the myStackSize variable as the size of “myStack” using the size function of stacks.

Line 14 is like line 9, but it creates an empty stack named “myTempStack”. This will be the stack that temporarily holds our stack of information so we can get the first record.

Lines 15 – 17 push the content into the “myTempStack” stack by popping each record in the “myStack” stack. The for loop know how many times to do this by using the myStackSize variable that was declared on line 8 and initialized on line 13.

Line 18 displays which caller is the current caller by popping it from the top of the “myTempStack” stack.

Line 19 is like line 13 in that it initializes the value of the myTempStackSize variable as the size of “myTempStack” using the size function of stacks.

Line 19 is also the beginning of the process of reverting the stack back to its original order with the first (oldest) entry removed.

Lines 20 – 22 are similar to lines 15 – 17 but the reverse process. They push content into the “myStack” stack by popping each record in the “myTempStack” stack. The for loop knows how many times to do this by using the myTempStackSize variable that was declared on line 8 and initialized on line 19.

Line 24 & 25 close out lines 7 & 6 respectively.

## Projectile Motion Worksheet #1

In my Principles of Technology class, we are starting to gear-up for a projectile motion project. The students will be working in teams and launching a water balloon at me from exactly 40 yards away.

In the first worksheet in the series, students were given a series of right triangles with sides A and B given. Sometimes the units were the same and other times they would have to convert units.

The students were asked to calculate the length of C in the most appropriate units and then calculate angle X using the trig function (sine, cosine, or tangent) of their choice.

All of my students were able to perform the first calculation using the Pythagorean Theorem. The second calculation, even through it was given step-by-step, was not completed by the majority of the students who are in Algebra I.

The claim was that they had never seen it before. Obviously, I countered with, “Well, you have now.”.

## Getting Hot in Physics

Well, to say that today did not go as expected would be the understatement of the school year!

My Principles of Technology class has been working on building model rockets as part of a unit that was analyzing the physics concepts of impulse, velocity, and acceleration, the chemistry concept of balanced chemical equations/reactions, and the engineering concept of technical drawing/documentation.

Today was the day that we launched. We had 6 small single-stage rockets to launch in addition to 2 small two-stage rockets.

EachÂ single-stage rocket was loaded with a single A-rated motor which would carry it to a total altitude of approximately 250 feet. EachÂ two-stage rocket was loaded with two C-rated motors which would carry it to a total altitude of approximately 1,800 feet!

Before going outside, we verified the weather conditions, which showed winds from the west at 7 MPH with guests to 11 MPH. The humidity was 41% and dropping. We decided to launch from the west side of the property with the idea that the winds would carry the rockets onto the soccer fields which had recently been watered.

Our first launch of the morning performed as expected and came down next to the roadway by the launch site.

Our second launch of the day did not perform as well. The first stage of the rocket fired as designed and carried the rocket to around 900 feet. Unfortunately, the first stage did not properly separate as designed and the rocket began to tumble back to the ground.

After a few seconds, the second stage ignited which sent the rocket flying on the path it was pointing at, which was toward the ground west of our launch location and it ignited the cardboard frame of the first stage which was now in a free-fall into the field to the west of the launch location.

The rocket came down about 100 yards west of the launch pad and the first stage landed about 30 yards to the east of the crash site. Unfortunately, since the first stage was on fire when it landed and it landed in a field of 1 meter tall grass/hay, the field was quickly engulfed in fire.

Ultimately, the crash resulted in the burning of approximately 1 acre of grassland which is fortunately owned by the school.

Because of the quick response of the Ferris Fire Department, the fire was quickly contained and everyone was safe with the only loss being the grassland, the rocket launcher, and the rocket launch stand.