class 8-10

Fermat's principle states that “light travels between two points along the path that requires the least time, as compared to other nearby paths.” From Fermat's principle, one can derive (a) the law of reflection [the angle of incidence is equal to the angle of reflection] and (b) the law of refraction [Snell's law].

The balloon that has been rubbed on your hair or clothing has collected electrical charges that we refer to as static electricity. When you move the balloon close to the CFL lightbulb the static electricity of the balloon begins to interact with the electrons inside and the light bulb illuminates

The electroscope is an early scientific instrument used to detect the presence of electric charge on a body. 

Water molecules are polar, they have a negative and a positive end. The negatively charged object attracts the positive end of the water molecules making the stream of water bend.

The faster an object vibrates, the higher the pitch of the sound. The length and thickness of the vibrating object also affects its pitch.

Slinky coil can be used to demonstrate longitudinal wave. In longitudinal wave, the direction of the wave is parallel to the direction of the vibration of the particle.

A push or a pull on an object is called a force. Forces applied to an object in the same direction count to one another. “If the two forces act in the opposite directions on an object, the net force acting on it is the difference between the two forces.”

When you apply pressure to the container, the Cartesian diver sinks, and when pressure is released, it rises.The experiment demonstrates the relationship between volume, pressure, and buoyancy, and it is a practical application of the gas laws and principles discovered by Descartes and his contemporaries

Capillary action is important for moving water (and all of the things that are dissolved in it) around. It is defined as the movement of water within the spaces of a porous material due to the forces of adhesion, cohesion, and surface tension.