Parabolic Mirrors and Real Images
When a function depends on multiple independent variables, the curly-d symbol denotes slopes calculated by jiggling only one independent variable at a time. This is a multivariable cousin to the derivative. We use this notation in future sections to keep track of how molecules are generated or degraded by different reactions.
Students are presented with a short lesson on the Coulter principle—an electronic method to detect microscopic particles and determine their concentration in fluid. Depending on the focus of study, students can investigate the industrial and medical applications of particle detection, the physics of fluid flow and electric current through the apparatus, or the chemistry of the electrolytes used in the apparatus.
Students investigate the property dependence between liquid and solid interfaces and determine observable differences in how liquids react to different solid surfaces. They compare copper pennies and plastic "coins" as the two test surfaces. Using an eye dropper to deliver various fluids onto the surfaces, students determine the volume and mass of a liquid that can sit on the surface. They use rulers, scales, equations of volume and area, and other methods of approximation and observation, to make their own graphical interpretations of trends. They apply what they learned to design two super-surfaces (from provided surface treatment materials) that arecapable of holding the most liquid by volume and by mass. Cost of materials is a parameter in their design decisions.
Students explore their peripheral vision by reading large letters on index cards. Then they repeat the experiment while looking through camera lenses, first a lens with a smaller focal length and then a lens with a larger focal length. Then they complete a worksheet and explain how the experiment helps them solve the challenge question introduced in lesson 1 of this unit.
How do strong and weak acids differ? Use lab tools on your computer to find out! Dip the paper or the probe into solution to measure the pH, or put in the electrodes to measure the conductivity. Then see how concentration and strength affect pH. Can a weak acid solution have the same pH as a strong acid solution?
Watch alpha particles escape from a Polonium nucleus, causing radioactive alpha decay. See how random decay times relate to the half life. (Previously part of the Nuclear Physics simulation - now there are separate Alpha Decay and Nuclear Fission sims.)
Predict how objects of various masses can be used to make a plank balance. Predict how changing the positions of the masses on the plank will affect the motion of the plank. Write rules to predict which way a plank will tilt when objects are placed on it. Use your rules to solve puzzles about balancing.
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.
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.
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.
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.
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.
Watch beta decay occur for a collection of nuclei or for an individual nucleus.
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.
Build an atom out of protons, neutrons, and electrons, and learn about its mass, charge, structure, and nomenclature.
When will objects float and when will they sink? Learn how buoyancy works with blocks. Arrows show the applied forces, and you can modify the properties of the blocks and the fluid.
When will objects float and when will they sink? Learn how buoyancy works with blocks. Arrows show the applied forces, and you can modify the properties of the blocks and the fluid.