Physics

When a fast moving train takes a curved path, it tends to move away tangentially off the track. In order to prevent this, the curved tracks are banked on the outside to produce the necessary centripetal force required to keep the train moving in a curved path.

Positive feedback is used in oscillators.

Conduction is heat transfer through stationary matter by physical contact.

Electric Motor converts electrical energy to mechanical energy.

If a body moves with a constant speed in a circle its velocity remains constant.

During thunderstorm you are travelling in a car. To protect yourself from the lightning you will have to remain in the car.

The density of gases depends upon the temperature. The higher the temperature, the more the molecules are spread out and the lower the density.

Stars come in lots of different colours, and their colour depends on the temperature of the star. We find that small stars are cool (less than 3000°C) with a red-ish appearance, whereas big heavy stars are hot (over 30,000°C), and have a blue-ish glow.

Effervescence is the escape of gas from an aqueous solution and the foaming or fizzing that results from a release of the gas. It leads to the formation of gas bubbles in a liquid. For example, when opening a bottle of champagne, beer or carbonated beverages such as soft drinks, the visible bubbles are produced by the escape from solution of the dissolved gas.