**8. Teaching with** *Angry Birds*

We described some topics where the computer game *Angry Birds* could be appropriate for teaching physics. It contains many mandatory topics of physics curriculum, and it can either be used as a motivational tool, where children could get more comfortable with physics while using ICT or it can be used as an experiment to show children simulation of actual physics. From the experiment, we could define exercises where children could get basic knowledge about physics and calculus behind it. In this chapter, we show an example of how we can teach the physics of projectile motion using the computer game *Angry Birds*. Before we can explain the physics of *Angry Birds*, we have to make footage of *Angry Birds* gameplay, and after that, we can analyze data in that footage. For that, we need some additional programs appropriate for classroom usage, for which we present some examples.

#### **8.1. LioLo Game Recorder**

The recommended software for making gameplay footage is a program called LoiLo Game Recorder. You can download it for free from their website [22] and install the program on your computer*.* LoiLo Game Recorder is a program that enables us to record game sessions. It also supports Motion-JPEG file format that provides with the best balance between file size and image quality. For our purpose, we recorded full-HD videos, and file size is still manageable. When you downloaded and installed the program, simply start the program and the game in which you want to make a recording. Before you start to play, press F6 on keyboard and program will start recording (Figure 9). After you finish playing, press key F6 again and the program will stop recording and save the footage in your PC's video directory. Now you can use the footage for analysis. To minimize the measurement errors at analysis of gameplay, the footage must be smooth and without delays [22]. We will do our analysis in program called Tracker.

**Figure 9.** This is the LoiLo Game Recorder's user interface where we can see options available in program. We can also see an example of the footage that we made in *Angry Birds*.

#### **8.2. Tracker**

Tracker is a free video analysis and modeling tool built on the open source physics (OSP) Java framework. It is designed to be used in physics education and can be easily run from USB drive. Requirements for using Tracker are small, and it only requires that you have installed Java 1.6 or higher. It has a variety of tools to help user to analyze the data from recording where we can read what happened with physical quantity on the graphs (Figure 10). To analyze data from recording, we simply start the program Tracker in which we can open video that we have made with the program Loilo and start the measurements with different tools [23]. Before we can acquire the measurements for discussing physics problem, we need to set starting point to place our bird in space. We do that with calibration tool where we set the coordinate system in the foot of slingshot, which will be our starting point. We also need our measuring unit, which in our case will be the slingshot size. When we determined starting point and basic measuring unit, we use tracking tool to track bird's movement in the footage. When tracking is finished, we see all measurements in the graphs, which we can analyze with measurement analyzing tool. The program Tracker also has a video-analyzing tool where we can depart video frame by frame. For final results, we use measurement-analyzing tools where the data are displayed in different graphs.

**Figure 10.** The program has many tools to offer; the most essential of them are the calibration tool, which we can find at the top; the measurement analyzing tools at the right; and the video analyzing tool at the bottom of program inter‐ face.

#### **8.3. Physics of** *Angry Birds*

about physics and calculus behind it. In this chapter, we show an example of how we can teach the physics of projectile motion using the computer game *Angry Birds*. Before we can explain the physics of *Angry Birds*, we have to make footage of *Angry Birds* gameplay, and after that, we can analyze data in that footage. For that, we need some additional programs appropriate

The recommended software for making gameplay footage is a program called LoiLo Game Recorder. You can download it for free from their website [22] and install the program on your computer*.* LoiLo Game Recorder is a program that enables us to record game sessions. It also supports Motion-JPEG file format that provides with the best balance between file size and image quality. For our purpose, we recorded full-HD videos, and file size is still manageable. When you downloaded and installed the program, simply start the program and the game in which you want to make a recording. Before you start to play, press F6 on keyboard and program will start recording (Figure 9). After you finish playing, press key F6 again and the program will stop recording and save the footage in your PC's video directory. Now you can use the footage for analysis. To minimize the measurement errors at analysis of gameplay, the footage must be smooth and without delays [22]. We will do our analysis in program called

**Figure 9.** This is the LoiLo Game Recorder's user interface where we can see options available in program. We can also

Tracker is a free video analysis and modeling tool built on the open source physics (OSP) Java framework. It is designed to be used in physics education and can be easily run from USB drive. Requirements for using Tracker are small, and it only requires that you have installed Java 1.6 or higher. It has a variety of tools to help user to analyze the data from recording where we can read what happened with physical quantity on the graphs (Figure 10). To analyze data from recording, we simply start the program Tracker in which we can open video that we have

see an example of the footage that we made in *Angry Birds*.

for classroom usage, for which we present some examples.

216 E-Learning - Instructional Design, Organizational Strategy and Management

**8.1. LioLo Game Recorder**

Tracker.

**8.2. Tracker**

When we have analyzed the data with the program Tracker, we can start talking about physics in games. Projectile motion is a case of motion which we can describe it as motion in two dimensions: vertical and horizontal. In this particular case, we can neglect air resistance because the game was not designed to include air resistance in projectile motion. We know that when we shot a bird slingshot, its initial speed (*v* → <sup>0</sup>) is

$$
\vec{\boldsymbol{v}}\_0 = (\boldsymbol{v}\_{0x'} \ \boldsymbol{v}\_{0y})\_\prime \tag{5}
$$

where *v*0*<sup>x</sup>* is the size of the horizontal component of initial velocity and *v*0*<sup>y</sup>* is the size of the vertical component of initial velocity [20]. The only force that is affecting the bird during the flight is gravitational force. That is why acceleration of bird is equal to the gravitational acceleration.

We also know that the horizontal component of velocity is not changing in size because acceleration only got vertical component. That is why we can define the movement of bird in time *t* :

$$\mathbf{x}\_{finishad} = \left(\upsilon\_{0x}\cos\theta\right)\mathbf{t} + \mathbf{x}\_{string\text{ }\prime} \tag{6}$$

where *x finished* is the location where bird has finished movement in time *t* in his horizontal path and *xstarting* is the initial location from where bird has started moving in horizontal path. *θ* is the angle by which we shot the bird from slingshot [19]. As a result, we get Figure 11, which shows us that the body was moving in horizontal direction with constant velocity *v*0*<sup>x</sup>* equal to 3.31 U/s [24].

**Figure 11.** From the measurement, we can read that the horizontal component of velocity (A) is 3.31 U/s, and we can see that dependency position from time is linear.

For motion in vertical direction, we know that acceleration is constant. That is why we can define motion in vertical direction as

$$\mathcal{Y}\_{h\text{light}} = (\upsilon\_{0y}\sin\theta)t - \frac{1}{2}gt^2 + \mathcal{Y}\_{\text{string}},\tag{7}$$

where *ystarting* is the starting height from which the birds was shot in vertical direction from angle *θ* and *yhighest* is the maximum height that the birds will reach in at time *t*. We also see that acceleration is equal to gravitational acceleration *g* if our game is happening on Earth. From the measurement, we see that vertical motion fits to quadric equation (Figure 12), which also shows us that acceleration in vertical direction is constant and is equal to –1.9 U/ s<sup>2</sup> [25].

We also know that the horizontal component of velocity is not changing in size because acceleration only got vertical component. That is why we can define the movement of bird in

where *x finished* is the location where bird has finished movement in time *t* in his horizontal path and *xstarting* is the initial location from where bird has started moving in horizontal path. *θ* is the angle by which we shot the bird from slingshot [19]. As a result, we get Figure 11, which shows us that the body was moving in horizontal direction with constant velocity *v*0*<sup>x</sup>* equal to

**Figure 11.** From the measurement, we can read that the horizontal component of velocity (A) is 3.31 U/s, and we can

For motion in vertical direction, we know that acceleration is constant. That is why we can

where *ystarting* is the starting height from which the birds was shot in vertical direction from angle *θ* and *yhighest* is the maximum height that the birds will reach in at time *t*. We also see that acceleration is equal to gravitational acceleration *g* if our game is happening on Earth. From

<sup>1</sup> ( sin ) , <sup>2</sup> *highest y starting y v t gt y* = -+ q

0

2

(7)

(6)

( 0 cos ) , *finished x starting x v tx* = + q

218 E-Learning - Instructional Design, Organizational Strategy and Management

time *t* :

3.31 U/s [24].

see that dependency position from time is linear.

define motion in vertical direction as

**Figure 12.** From Equation (7), we can see that acceleration (A) in vertical direction is *a*/2, which gives us a result accel‐ eration equal to 1.9 U/ s<sup>2</sup> . From the measurement, we can also read the vertical component of velocity (B), which is 2.8 U/s, and height (C), which is 0.8 U.

From the result, we wanted to determine what was the size of our basic unit. We measured acceleration in vertical direction as 1.9 U/ s<sup>2</sup> . We placed our experiment on Earth so acceleration should be equal to gravitational acceleration, which is 9.8 m/ s<sup>2</sup> [24,25]. From that, we can calculate what was the size of our basic unit, and we get the result that our slingshot was 5.1 m high because the size of the slingshot was set as our basic unit. When we get our basic unit, we can calculate our velocity in vertical and horizontal directions so that we simply multiply our measured values with 5.1 m, and as result, we get that *v*0*<sup>y</sup>* is 14.2 m/s and *v*0*<sup>x</sup>* is 16.7 m/s. From this point, we can calculate initial velocity as follows:

$$
\upsilon \upsilon\_0 = \sqrt{\upsilon\_{0x} \,^2 + \upsilon\_{0y} \,^2} \,\, \, \, \, \tag{8}
$$

and we get that *v*0 is 21.9 m/s. From these measurements, we can also calculate our starting height *hstarting*, which is 4.2 m. When we obtain the starting height, we can also calculate the maximum height as follows:

$$h = \frac{\upsilon\_{0y}^2}{\mathbf{2g}} + \ h\_{\text{starting}}.\tag{9}$$

We get that the maximum height *h* is 14.5 m. It is also interesting to know from which angel did we shoot the bird:

$$\theta = \tan^{-1}(\frac{v\_{0y}}{v\_{0x}}) \tag{10}$$

As a result, we get *θ* = 40.4 ° . When we all needed information, we can also calculate the range *d* of the bird's flight using the following equation:

$$d = \frac{\upsilon\_0}{g} \sqrt{\upsilon\_0^2 + 2gh\_{\text{string } \prime}} \tag{11}$$

where we get range corresponding to value 52.8 m. We get a similar result when the range is 10.5 U, which is 53.0 m. We see that the range that we calculated is not the same as the range that we measured. We can explain that as an error in measurements.

#### **8.4. Use of example in classroom**

We have seen how we can analyze physics with the red angry bird, which does not have any special abilities. This type of analysis and understanding would be more appropriate for pupils in secondary school, in which pupils could use this particular experiment to determine the actual size of birds and the actual size of the slingshot, like we have shown in our example. We can also use experiment for teamwork, where we could divide pupils in two groups. the first group would have to explain the physics of vertical motion, and the second group would have to explain the physics of horizontal motion. At the end of the experiment, both explan‐ ations can be merged, and the physics of projectile motion can be explained. Our example can be also used in primary school, where we would have to lower the difficulty of tasks for pupils. We could teach them how to use the programs LoiLo and Tracker for simple analysis not only in *Angry Birds* but also in any other experiment footage. With this experiment, they can get familiar with graphs and errors in measurement. We also know that there is much more physics that can be explained with the use of *Angry Birds* for physics lessons. For additional work, students could explore the initial acceleration and midair acceleration of the yellow angry bird when we use his special ability. It would be also interesting to check the physics background of the blue angry bird, where students could check what is happening with momentum when he splits into three same-sized birds and if the mass of all three birds is the same. We already mentioned materials that show up in the game. For additional project work, students could analyze how different angry birds affect the same material.

#### **9. Research**

We showed an example of an experiment that could be used in the class. However, the question is if teachers would even use *Angry Birds* as a didactical tool. That is why we started research where we wanted to see teachers' responses on the proposal of teaching with *Angry Birds*. Our targeted group of teachers was mostly middle-aged teachers (age 36 years and older). We know that the use of ICT is in average a bigger problem in older teachers rather that new young teachers. That is why the middle-aged group is much more interesting. On the question if they know the computer game *Angry Birds*, 35% of the teachers answered yes (Figure 13), which is actually impressive according to age-group that was questioned.

**Figure 13.** Chart where we can see how many teachers know the computer game *Angry Birds*.

We get that the maximum height *h* is 14.5 m. It is also interesting to know from which angel

1 0 0 tan ( ) *<sup>y</sup> x*

q

0 2

that we measured. We can explain that as an error in measurements.

analyze how different angry birds affect the same material.

*<sup>v</sup> d v gh g*

*d* of the bird's flight using the following equation:

220 E-Learning - Instructional Design, Organizational Strategy and Management

**8.4. Use of example in classroom**

**9. Research**

*v v*

As a result, we get *θ* = 40.4 ° . When we all needed information, we can also calculate the range

<sup>0</sup> 2 , *starting*

where we get range corresponding to value 52.8 m. We get a similar result when the range is 10.5 U, which is 53.0 m. We see that the range that we calculated is not the same as the range

We have seen how we can analyze physics with the red angry bird, which does not have any special abilities. This type of analysis and understanding would be more appropriate for pupils in secondary school, in which pupils could use this particular experiment to determine the actual size of birds and the actual size of the slingshot, like we have shown in our example. We can also use experiment for teamwork, where we could divide pupils in two groups. the first group would have to explain the physics of vertical motion, and the second group would have to explain the physics of horizontal motion. At the end of the experiment, both explan‐ ations can be merged, and the physics of projectile motion can be explained. Our example can be also used in primary school, where we would have to lower the difficulty of tasks for pupils. We could teach them how to use the programs LoiLo and Tracker for simple analysis not only in *Angry Birds* but also in any other experiment footage. With this experiment, they can get familiar with graphs and errors in measurement. We also know that there is much more physics that can be explained with the use of *Angry Birds* for physics lessons. For additional work, students could explore the initial acceleration and midair acceleration of the yellow angry bird when we use his special ability. It would be also interesting to check the physics background of the blue angry bird, where students could check what is happening with momentum when he splits into three same-sized birds and if the mass of all three birds is the same. We already mentioned materials that show up in the game. For additional project work, students could

We showed an example of an experiment that could be used in the class. However, the question is if teachers would even use *Angry Birds* as a didactical tool. That is why we started research where we wanted to see teachers' responses on the proposal of teaching with *Angry Birds*. Our


= + (11)

did we shoot the bird:

With this, we have determined our group of teachers who actually know the game. Later on, we wanted to know how well they know the game. Hence, we set some common questions about the effects of the birds in the game and which of the physical content they see in the game is also included in physics curriculum. As a result, we learned that teachers who played *Angry Birds* know the game pretty well; 83% knew the effects of the birds in the game. The more interesting part comes when they had to determine the physical contents they found in the game, and the result was amazing. We found that physics teachers have noticed 9 different physics themes (Figure 14) in the computer game *Angry Birds*, which shows us that game really is suitable for physics class.

**Figure 14.** In the chart, we can see what teachers have found in the game *Angry Birds*: heat, projectile motion, gravity, elastic collision, buoyancy, momentum, astronomy, wave, and friction. The vertical axis shows the percentage of teach‐ ers who found certain physics content in the game. The horizontal axis shows the different physics contents.

We figured out that teachers can definitely see that game contains content for teaching physics. We also wanted to gain insight what teachers think about the suitability of the game in teaching physics in elementary and high school. Thus, we asked them how appropriate do they find the computer game *Angry Birds* for teaching physics in elementary school. None of teachers evaluated the computer game *Angry Birds* as inappropriate, and more than half of them find it appropriate for teaching physics (Figure 15).

**Figure 15.** On the vertical axis, there is percentage of teachers who evaluated suitability for elementary school from 1 to 6, where 1 indicates completely inappropriate and 6 indicates perfectly suitable for teaching physics in elementary school, which could be found on the horizontal axis. We see that more than half of teachers found the computer game *Angry Birds* for teaching in elementary school as appropriate; 22% of them found it also perfectly suitable for teaching physics in elementary school.

We also asked them how they would evaluate the suitability of the computer game *Angry Birds* for lessons in physics in high school (Figure 16). We got results that more than half of teachers find it appropriate for teaching physics in high school.

**Figure 16.** On the *y* axis, there is a percentage of teachers who evaluated suitability for high school from 1 to 6, where 1 indicates completely inappropriate and 6 indicates perfectly suitable for teaching physics in elementary school, which could be found on the *x* axis; 11% of them found it also perfectly suitable for teaching physics in high school.

In our survey, we also asked if the computer game *Angry Birds* is appropriate as a motivational tool in lessons in elementary and high school. As a result, 78% of the teachers find the computer game *Angry Birds* as a great motivational tool for both elementary and high school. The most impressive result was when we asked them if they would use the game for teaching physics. All of the teachers that know the computer game *Angry Birds* would use it for teaching physics.

#### **9.1. Methodology**

We figured out that teachers can definitely see that game contains content for teaching physics. We also wanted to gain insight what teachers think about the suitability of the game in teaching physics in elementary and high school. Thus, we asked them how appropriate do they find the computer game *Angry Birds* for teaching physics in elementary school. None of teachers evaluated the computer game *Angry Birds* as inappropriate, and more than half of them find

**Figure 15.** On the vertical axis, there is percentage of teachers who evaluated suitability for elementary school from 1 to 6, where 1 indicates completely inappropriate and 6 indicates perfectly suitable for teaching physics in elementary school, which could be found on the horizontal axis. We see that more than half of teachers found the computer game *Angry Birds* for teaching in elementary school as appropriate; 22% of them found it also perfectly suitable for teaching

We also asked them how they would evaluate the suitability of the computer game *Angry Birds* for lessons in physics in high school (Figure 16). We got results that more than half of

**Figure 16.** On the *y* axis, there is a percentage of teachers who evaluated suitability for high school from 1 to 6, where 1 indicates completely inappropriate and 6 indicates perfectly suitable for teaching physics in elementary school, which could be found on the *x* axis; 11% of them found it also perfectly suitable for teaching physics in high school.

teachers find it appropriate for teaching physics in high school.

it appropriate for teaching physics (Figure 15).

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physics in elementary school.

For our research, we used free online survey tool 1ka.si [26]. The tool offers many options to design an electronic survey. We took into account all basic rules of making survey where we limited the number of questions per page on 5 and separated the different topics of question in separate pages so the survey itself was not too harsh for respondents. In the survey, we also made a break point where we eliminated teachers who do not know the computer game *Angry Birds*. If they answered "no" on a question where we asked them if they know the computer game *Angry Birds*, the survey was finished; if they answered "yes," they could continue with the survey. We sent our survey through e-mail. The results that we introduced were analyzed in Excel table, where we merged our results in charts appropriate for the type of data that we got. In the research, we included 41 physics teachers who finished their study between the year 2005 and 2015 at our faculty and students of educational physics study. We got the response of 26 persons, 9 of them ware familiar with the game *Angry Birds*.
