Ever wondered how you can build a toy car using materials you can find at home? How do you design it to get it to travel the farthest?
During the May holidays, we invited Dr Ho Shen Yong to carry out “Project Toy Car” to engage our STEM Club students. Dr Ho is the Associate Dean (Academic) of the College of Science in NTU and Principal Lecturer in the School of Physical and Mathematical Sciences. He teaches Engineering Physics and was designated NTU Educator of the Year in 2018.
The students were excited to participate in the ‘Live’ Zoom session upon hearing the title of the activity – Project Toy Car. Everybody had the same question – “Are we really going to build a toy car?”
At the start of the session, Dr Ho, who believes in giving students the opportunity to think for themselves as that helps them to be challenged and motivated to learn, wanted to find out more about the students’ prior knowledge. He asked if anybody knew about Newton’s 3rd Law of Motion. To his surprise, a number of students were able to respond correctly as well as provide examples about it. One of the Primary 5 members, Qihan, answered proudly, “Yes! We had learnt this during one of the STEM Club activities.”
Dr Ho shared with the students numerous advanced physics concepts. Although those concepts were not usually taught at the primary level, he made them come alive for the students by sharing their applications in daily life. Dr Ho went on to discuss various considerations for building the car by showing videos of ingenious inventions. He asked the students to think about the materials that they could use to power and propel the toy car forward.
Then came the challenge. The students had one week to create a toy car using only materials that they could find at home. There would be a competition to find out whose toy car could travel the farthest distance.
Jonathan from Primary 5 could not decide which type of energy he should harness for his design. “I’m not sure if a toy car using wind energy from an electric fan or elastic potential energy from a twisted rubber band would move further.”
His classmate, Kristelle, suggested, “Why not use both types of energy?”
Qiyu from Primary 3 had a longer list of considerations. From the interaction with Dr Ho during the session, he realised that many variables such as the size, texture and thickness of the wheels, the mass of the car, the tightness between the wheels and the axles, and thickness of the axle were factors that could affect the distance travelled by the toy car.
The students submitted videos of their prototypes, which ranged from using balloons and sails to rubber bands to power their toy car. Dr Ho looked through them and provided individual feedback to the students. For some, he suggested adding rubbery tape around the circumference of the wheels or adding a weight to help improve the grip with the ground (desired friction). At the same time, he noticed that undesired friction was created for some of the cars, for example, when the wooden stick axle connecting the wheels was rubbing against the styrofoam body of the car. He also gave other suggestions to improve the design, such as aligning the wheels for smoother motion and controlling the release of the energy by slowing down the uncoiling of the rubber band.
Dr Ho shared, “It was a fun experience explaining Science and Technology to primary school children. Probably until we try to create or make something, we will not see the challenges. This toy car project is an opportunity to learn about Science and also learn about learning. It is important that the children have taken a first step, as ‘a journey of a thousand miles begins with a single step’ – no matter how small the first step is. We also often just look at the end product but not the hard work in the process, but ‘all things are difficult before they are easy’.”
To bring home the point that we should persevere and not be afraid to learn from failure, Dr Ho shared a video, “Early Flying Failures Stock Footage”. The airplane that we take for granted today had gone through many iterations and the early inventors did not give up despite not succeeding at first.
As our students work on improving the design of their toy cars, may they also embrace the spirit of trying and improving an important part of the learning process!