Innovative Teaching Aid

If we place a coin on top of a book, then we pull the book quickly, the coin will stay at the same position, isn't it? While travelling on a moving bus, we will experience a forward movement when the bus suddenly stop. These are typical examples that always been used by teachers at school in order to explain the concept of inertia. But many students still do not understand how to relate inertia with mass. Moreover, there is no proper experiment for inertia included in The Physics SPM curriculum. I found that most teachers just tell and ask students to just imagine the effect of inertia instead of showing them the real effect. Hence, I decided to design and develop an experimental inertia kit s shown in Figure 1. 

Figure 1: Inertia Kit

An innovative teaching material is required in order to visualize the concept of inertia among students and to improve their understanding. We build an Inertia Kit that is affordable and portable. Our innovation of Inertia Kit is able to demonstrate inertia better as we use a trolley that move smoother substituting the ‘book’. We used a toy car as the object that stay on the track that has been permanently attached onto the trolley. For the similar set up, the trolley can also be used to demonstrate a ‘moving bus’ and the toy car acts as a passenger. Then, to prove the concept of inertia through the trolley-toycar motion, we used Tracker software for the video analysis. 

The apparatus used for this experiment is the combination of the apparatus from physics laboratory at schools and some are low cost materials that have been purchased. The trolley and the wooden blocks are from the laboratory while the toy car and the curtain railings are new materials. An inertia kit is build using the existing materials from school’s laboratory. The trolley has been modified by attaching curtain railings onto it. The railing acts as a track for a toy car.

⏩Below is the procedure of conducting this experiment:

Figure 2.1: Inertia Kit -  top view - initial

Figure 2.2: Inertia Kit -top view - final

1. Place the toy car on the trolley set as in Figure 1 & 2.1

2. Place the set-up on a table.

3. Clamp a connecting rubber band at the table sides.

4. Move the inertia kit to the left until the rubber band is stretched to 15 cm as in Figure 2.2.

5. Release the kit and simultaneously record the video of the movement.

6. Analyse the video using Tracker software and fill the data in Table 2.

7. Repeat steps (4) to (6) with an addition of 450 g load on the toy car.

⏩Result:

Figure 3: Result from Tracker

Based on the graph in Part 1, it is proved that the velocity is constant even though the trolley is stopped finally. The red-dots line refers to the velocity of trolley set and the blue-dots line represents the velocity of the toy car. Theoretically the velocity of the toy car supposed to remain constant. However, the data shows that there is a slight decrement in its velocity due to possible friction between toy car tires and body. The decrement is very small in magnitude. 

Due to the time constraint, as students as running out of time finishing the syllabus, I did not have any opportunity to introduce this experiment to my students. Then i passed it to my sister who also teach Physics in middle school. My sister taught her students in school about inertia using this inertia kit. All students enjoyed this experiment and they were able to understand the concept easily.  The developed inertia kit allows students to learn actively because they can engage themselves during the experiment.

Figure 8: Video recording of the experiment

Thank you, 

Ummi Atiah Mohamad 

KMPk 

                                                          ~ May it Benefits You ➽💕