Photoelectric Effect The photoelectric effect is the phenomenon that the electrons pop out when a light beam incident on a metal surface. It can be thought that the energy of light is transformed into the form of electrical energy. However, … more
● It’s a tube. The radius of the tube is outside: inside = 0.75: 1. There is no rolling friction. ● It’s a tube. The radius of the tube is outside: inside = 0.5: 1. There is no rolling friction. … more
Potential energy The potential energy of an object is the energy stored in an object or system. Denoted as Ep. Generally speaking, potential energy refers to potential energy caused by gravity and is proportional to an object’s mass and height. … more
Potential energy due to gravity Lifting heavy objects increases the potential energy of the object. The amount of work done when lifting an object of mass m by height h can be obtained as (Potential energy by gravity) Ep(J) = … more
Conservation of Mechanical Energy If you look at the roller coasters, you can find something interesting. That’s right. There is no engine on the roller coaster. When we lift the roller coaster to the highest point, then the roller coaster … more
Kids have the know-how, but they can’t tell the principal. “How can you go so high?” Some principles are difficult to describe in words in the world, even if everyone knows. I think one of them is how to ride … more
Mechanical energy Mechanical energy is the sum of potential and kinetic energy. Mechanical energy = potential energy + kinetic energy Em = EP + EK Mechanical energy conservation Without friction, the sum of an object’s initial mechanical energy is equal … 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
Slingshot effect Suppose you throw an elastic ball to a moving train. And since the train’s mass is huge, let’s assume that the ball’s mass is negligible compared to the mass of the train. At this time, if the speed … more
Heat engine A heat engine is a machine that operates by moving energy from a hot space to a cold space. In this process, the heat engine converts some of the heat energy into mechanical energy. All the heat engines … more
Kinetic energy All moving objects have kinetic energy. The kinetic energy Ek of an object with a mass of ‘m’ and a velocity of ‘v’ can be calculated as follows. \[E_{ k }=\frac { 1 }{ 2 } m{ v … more
A heat engine A heat engine is a machine that moves by moving energy from a hot space to a cold space. In this process, the heat engine converts some of the heat energy into mechanical energy. All heat engines … more