Theo Jansen He is the leading artist of kinetic art with the nickname of Da Vinci in the 21st century. He is famous for making wind-driven structures using simple materials such as PET bottles, tubes, and cable ties. Since 1990, … more
Three elements of force When a force acts on an object, the object’s motion varies depending on the Three elements of force. That is the magnitude, direction, and point of action. Therefore, when displaying a force, you must indicate the … more
Why is the submerged volume important to understand buoyancy? It is so famous that the 3rd-century Greek philosopher Archimedes shouted “Eureka!” and ran out of the bathhouse naked. （What did Archimedes find out? – Quotations from middle school science textbooks） … more
Projectile Motion When you throw an object, the object falls with a certain curve. The object performs a parabolic motion. This is a motion on a two-dimensional plane, not a straight line. To understand this movement, it is necessary to … more
Let’s measure my weight on several planets with the scale that we used on Earth. Newton explaining the gravity mathematically Every object has a gravitational field around it and attracts surrounding objects. The strength of this gravitational field is proportional … more
Motion of changing speed When a force of a certain size and direction acts on an object, the object moves at a constant rate of speed. These movements are easy to find around us. For example, the speed of a … more
Elevator and inertia Elevators are an excellent place to feel the inertia force. Consider the case of taking an elevator and trying to go up from the lower floor. When you press the button that goes up, you suddenly feel … more
This experiment is, You can experiment with heavy golf balls and light ping pong balls. Put a ping pong ball on top of the golf ball and drop it as it is. The golf ball hits the floor first. As … more
Parabolic motion Let’s think about the motion of throwing an object horizontally. There is no horizontal force when there is no air resistance, so there is no change in speed. This time, let’s consider a dropping. If the initial velocity … more
Inertia When the bus starts suddenly, the body momentarily leans backward. On the other hand, when the bus stops, the body is leaned forward. This is due to the nature of the object to maintain its current state of motion … more
How cannonball become an artificial satellite? a. Imagine that a cannonball falls in a parabolic curve. The trajectory the cannonball draws is actually part of an elliptical orbit centered around the Earth. The center of the Earth corresponds to the … more
