By Veeshan Narinesingh, STEM program leader
Dr. George Grant
This week in their STEM sessions, our young men worked on PowerPoint presentations for Black History Month. Their presentations celebrated the long history of African American innovators, with a focus on Dr. George Grant, a son of former slaves and one of the first African Americans to graduate from Harvard’s dental school.
Grant was also the inventor of the golf tee. Before his invention, golfers teed the ball up on little mounds of sand and had to carry buckets of sand during their rounds.
For NY1’s visit, our students broke out their golf club pendulums to study Newton’s second law, or, in more familiar form, F=ma (force=mass multiplied by acceleration). In this experiment, students raised their pendulums to the same height and let them strike balls of varying mass (golf ball, almostGOLF ball, ping-pong ball) but similar volume. They theorized that by keeping the force constant and increasing the mass of the ball, the acceleration and in turn the velocity of the balls would decrease. By intuition and mathematics, this theory makes perfect sense, right? The heavier the ball, the slower it should be.
The young men collected their data by timing how long each ball took to traverse one meter after being struck. They learned how Microsoft Excel can be a powerful tool in data collection, manipulation, and analysis. The students developed their own algorithms to calculate velocity, average their data, and calculate kinetic energy. Some of them were even able to plot their data!
The data, however, did not reflect what the young men had theorized. Because the mass distribution of the balls varied, so did the moment of inertia, so the acceleration and velocity were inconsistent.
The students learned a valuable lesson that all scientists must understand: some things that seem intuitive and straightforward can have hidden complexities. That’s why experiments and data analysis are so important.
For the next experiment on this topic, our students will further study acceleration and F=ma with some of the cool gadgets we have waiting for us in the Learning Center.