Experiment with a helium balloon, a hot air balloon, or a rigid sphere filled with different gases. Discover what makes some balloons float and others sink.
Students explore static electricity by rubbing a simulated balloon on a sweater. As they view the charges in the sweater, balloon, and adjacent wall, they gain an understanding of charge transfer. This item is part of a larger collection of simulations developed by the Physics Education Technology project (PhET). The simulations are animated, interactive, and game-like environments.
Why does a balloon stick to your sweater? Rub a balloon on a sweater, then let go of the balloon and it flies over and sticks to the sweater. View the charges in the sweater, balloons, and the wall.
Explore the origin of energy bands in crystals of atoms. The structure of these bands determines how materials conduct electricity.
Explore the origin of energy bands in crystals of atoms. The structure of these bands determines how materials conduct electricity.
Look inside a resistor to see how it works. Increase the battery voltage to make more electrons flow though the resistor. Increase the resistance to block the flow of electrons. Watch the current and resistor temperature change.
Look inside a battery to see how it works. Select the battery voltage and little stick figures move charges from one end of the battery to the other. A voltmeter tells you the resulting battery voltage.
Look inside a battery to see how it works. Select the battery voltage and little stick figures move charges from one end of the battery to the other. A voltmeter tells you the resulting battery voltage.
Students learn about material properties, and that engineers must consider many different materials properties when designing. This activity focuses on strength-to-weight ratios and how sometimes the strongest material is not always the best material.
Explore bending of light between two media with different indices of refraction. See how changing from air to water to glass changes the bending angle. Play with prisms of different shapes and make rainbows.
Bernoulli's principle relates the pressure of a fluid to its elevation and its speed. Bernoulli's equation can be used to approximate these parameters in water, air or any fluid that has very low viscosity. Students learn about the relationships between the components of the Bernoulli equation through real-life engineering examples and practice problems.
Students use the scientific method to determine the effect of control surfaces on a paper glider. They construct paper airplanes (model gliders) and test their performance to determine the base characteristics of the planes. Then they change one of the control surfaces and compare the results to their base glider in order to determine the cause and effect relationship of the control surfaces.
This lesson begins with a demonstration prompting students to consider how current generates a magnetic field and the direction of the field that is generated. Through formal lecture, students learn Biot-Savart's law in order to calculate, most simply, the magnetic field produced in the center of a circular current carrying loop. For applications, students find it is necessary to integrate the field produced over all small segments in an actual current carrying wire.
How does the blackbody spectrum of the sun compare to visible light? Learn about the blackbody spectrum of the sun, a light bulb, an oven, and the earth. Adjust the temperature to see the wavelength and intensity of the spectrum change. View the color of the peak of the spectral curve.
Rockets need a lot of thrust to get into space. In this lesson, students learn how rocket thrust is generated with propellant. The two types of propellants are discussed and relation to their use on rockets is investigated. Students learn why engineers need to know the different properties of propellants.
Students make a skydiver and parachute contraption to demonstrate how drag caused by air resistance slows the descent of skydivers as they travel back to Earth. Gravity pulls the skydiver toward the Earth, while the air trapped by the parachute provides an upward resisting force (drag) on the skydiver.
Students learn how engineers gather data and model motion using vectors. They learn about using motion-tracking tools to observe, record, and analyze vectors associated with the motion of their own bodies. They do this qualitatively and quantitatively by analyzing several examples of their own body motion. As a final presentation, student teams act as engineering consultants and propose the use of (free) ARK Mirror technology to help sports teams evaluate body mechanics. A pre/post quiz is provided.
Students are introduced to the challenge question, which revolves around proving that a cabinet x-ray system can produce bone mineral density images. Students work independently to generate ideas from the questions provided, then share with partners and then with the class as part of the Multiple Perspectives phase of this unit. Then, as part of the associated activity, students explore multiple websites to gather information about bone mineral density and answer worksheet questions, followed by a quiz on the material covered in the articles.
Students revisit the mathematics required to find bone mineral density, to which they were introduced in lesson 2 of this unit. They learn the equation to find intensity, Beer's law, and how to use it. Then they complete a sheet of practice problems that use the equation.
Students examine an image produced by a cabinet x-ray system to determine if it is a quality bone mineral density image. They write in their journals about what they need to know to be able to make this judgment. Students learn about what bone mineral density is, how a BMD image can be obtained, and how it is related to the x-ray field. Students examine the process used to obtain a BMD image and how this process is related to mathematics, primarily through logarithmic functions. They study the relationship between logarithms and exponents, the properties of logarithms, common and natural logarithms, solving exponential equations and Beer's law.