Physics is an important science because it explains the world we live in and provides the foundation for other sciences, such as chemistry and meteorology. Physics studies the fundamental concepts of matter, energy, space and time, and the interactions between these properties. High school students looking for simple physics experiments can study the concepts of light, static electricity and thermodynamics.
Ever wonder why the sky is blue, but a sunset is red? Use a flashlight, transparent rectangular container, a cup of milk and some water to find out why.
Fill the container three-quarters full of water and shine the flashlight into the side of the container. Observe the light from the opposite side and the end of the container. At most, a few dust particles, white in appearance, might be seen where the beam passes through. Now stir 1/4 cup of milk into the water. Observe the light from the opposite side and the end of the container. From the other side, the light may seem blue, and from the end, the light may seem yellow. Note the width of the beam. Repeat until all of the milk is added, and you'll notice after each addition that the blue darkens and the yellow turns to orange. Also note that the width of the beam increases.
Why did the light appear two different colors, depending upon the angle? Light travels in a straight line unless it encounters particulates that cause the beam to scatter. The more milk, which contains fat and protein particles, you add into the water, the more the light scatters, with the blue bending while the red and orange continue in more of a straight line. As for the sunset, because of the sun’s path, the light has farther to travel at sunset and encounters more dust particles in the atmosphere.
Static electricity can shock an unsuspecting person, and it can also move objects. Use a nylon comb and a faucet to watch static electricity bend water.
Turn the faucet on so that water 1/16 inch in diameter flows from the tap. Run the comb through someone’s hair a few times. Hold the comb 3 to 4 inches below the tap with the teeth of the comb an inch from the water stream. Note what happens. Move the comb closer and observe what happens. Run the comb through hair again and see if it changes the results. Try adjusting the water stream to see if it makes a difference. Finally, try different size combs and repeat.
The process of combing hair creates static electricity. One object becomes negatively charged by the gain of electrons, while the other object becomes positively charged by the loss of electrons. Holding the comb near the stream of water causes electrons from the water to jump to the charged comb and results in the stream moving toward the comb. The combed hairs might also be repelling each other, since each strand holds the same charge and like charges repel.
What does the weatherman mean by "high pressure" and "low pressure"? A hard-boiled egg, an old-fashioned glass milk bottle and some matches can help you find out.
Peel a cooled, hard-boiled egg. Simultaneously, light three matches and drop them in an empty glass bottle. Quickly cover the opening with the egg. After the matches extinguish, watch as the egg is sucked into the bottle.
The heat from the matches causes the air sealed into the bottle to expand. After the matches go out, the air cools and contracts. The pressure inside the bottle becomes lower than the pressure outside the bottle. As the pressure equalizes, the egg enters the bottle.