Magnet is an object that can attract iron and produce a magnetic field outside it. The magnetic pole pointing to the north is called the north pole or the N pole, and the magnetic pole pointing to the south is the pole or the S pole. Magnet dissimilar is sucked, the same pole is excluded. Magnet is divided into permanent magnets and non-permanent magnets, non-permanent magnets are usually generated in the form of electromagnets, the use of current to strengthen the magnetic field.
Gravity, also known as gravitation, refers to the quality of objects between the role of mutual attraction, but also the source of the weight of the object. The quality of the planet is different, the gravitational force is different, the mass of the moon is only one-sixth of the earth, so gravity is one-sixth of the earth. On the moon to jump hard, you can jump higher than the earth farther.
When an object slides or is about to slide on the surface of another object, it will produce a force to prevent relative movement on the contact surface. It is called friction force. The friction force will convert the kinetic energy of the object into heat energy. Friction is from the electromagnetic force between charged particles, including electrons, protons, atoms and molecules between the force.
Fluid mechanics is a branch of mechanics, is to study the fluid (including gas, liquid and plasma) phenomenon and related mechanical behavior of science. The way of fluid movement is influenced by the nature of the fluid, the shape of the flow path, the magnitude of the applied pressure, and the flow and deformation are the most significant properties of the fluid.
Object (or system) state of motion remains the same, because the energy is conserved, can not be created or eliminated, can only be converted into different forms. For example, when the rocket takes off, a large amount of gas is ejected vertically downward. According to the principle of conservation of momentum, the rocket obtained upward momentum, the size should be just the same momentum with the gas down.
The snake is composed of several pendants, and the shape of the traveling wave appears after swinging. The wavelength changes into the state of chaos over time, and can not see the waveform. Then the process of separating the ball from the two balls is as if the direction of the first half cycle is repeated, but the direction of the traveling wave is changed, contrary to the direction of the first half of the cycle, and finally returns to the initial straight line state.
When the light from a medium into another medium, back to the original media light, called the reflection, into another medium, called the refraction. When the light reaches a different medium, such as: smooth mirror, will make most of the light reflected back, parallel to the beam after the smooth mirror is still parallel to the injection.
When you pass the seven hurdles, get seven medals, as long as the answer to the last three questions, you can get the ultimate supreme science medal.