August 28, 2006
New and Revised Gizmos
Over the past few weeks we have updated and released several Gizmos. Here is a list:
Pulley Lab: Explore the dynamics of pulleys in this new Gizmo, our first on simple machines.
Orbital Motion - Kepler's Laws: Adjust the starting velocity and position of a planet, release it and see what happens! Special features of this Gizmo will allow students to discover each of Kepler's Laws.
Doppler Shift Advanced: This Gizmo, which complements Doppler Shift, has a quantitative focus. Students use the data they gather to write equations for wave frequency in front of and behind a moving source, or for a stationary source and a moving observer.
Freefall Laboratory : We have added new objects, a free-body diagram to show forces, and a variety of manual settings to accomodate a wide variety of experimentation. The Exploration Guide now allows students to calculate the final velocity for objects falling in a vacuum from a known height.
Air Track: We have updated the graphics and interface of this classic Gizmo, and added an exploration guide and assessment questions. Students can discover conservation of momentum and energy for elastic and inelastic collisions.
Limiting Reactants: We have updated the layout and curriculum materials for one of our most visually stunning Gizmos. Not only is this a great Gizmo for teaching about limiting reactants, but it is an exceptional depiction of a chemical reaction as well.
Inclined Plane - Sliding: Our old Inclined Plane Gizmo is in the process of being replaced by a series of Gizmos. In this Gizmo, the focus is on energy conversions for sliding objects. Future related Gizmos will focus on rolling objects, vector diagrams, and simple machines.
Well the verdict is in, and Pluto is out. In a vote last Tuesday, the International Astronomical Union voted on a new definition of "planet" that would exclude Pluto and other icy objects in the outer parts of the solar system. Ironically, the new definition stipulates that a planet has "cleared the neighborhood around its orbit," which would exclude the gas giant Neptune as well (Pluto's orbit overlaps the orbit of Neptune). However, Neptune was officially reinstated as a planet by special footnote. Pluto (and other newly discovered bodies, such as Xena and Sedna) is now a "dwarf planet."
Unlike textbooks, ExploreLearning was able to respond to the change quickly by adding a few notes to our Solar System Explorer Gizmo. We left Pluto in because it has such an interesting orbit, but made sure we referred to it as a "dwarf".
On the topic of planets, check out our brand-new Orbital Motion - Kepler's Laws Gizmo. In this spectacular new Gizmo, you can change the position, mass, and velocity of a planet, then observe its motion around a central star. It was a great surprise to me that almost any starting configuration results in a stable orbit - things don't gradually spiral in to the star as you might expect. Just as Kepler did in the 17th century, you will discover that the planetary orbits conform to some very interesting laws.
August 16, 2006
Mercury, Venus, and the Rest?As a student I only had to remember the name of nine planets in our solar system. I managed to remember all. Currently almost 2,500 astronomers are meeting in Prague and working on a definition for what a planet really is. There is a chance we could end up with twelve planets, dozens more, or maybe just eight! If changes occur we'll be sure to update our Solar System Explorer Gizmo the following day.
August 11, 2006
Electrons and Northern LightsPhysicist James A. Van Allen passed away earlier this week. During his very long career he did a wealth of research in magnetospheric physics. The Van Allen belts were named after him in 1958.
One of the highlights of this early research was the 1953 discovery of electrons believed to be the driving force behind the northern and southern lights.For more information go ahead and read the Wikipedia entry about his career.
August 01, 2006
Golf Range Gizmo Updated
This week we have updated one of our oldest and most popular Gizmos, Golf Range! The unique combination of sports and projectile motion makes this a fun and vital physics lesson. Along with great-looking new graphics and a complete set of curriculum materials, we have added several new features:
- Horizontal and vertical velocity vectors, allowing students to see which component of velocity changes as the ball travels through the air.
- A grid and crosshairs, allowing students to plot the parabolic trajectory of the ball.
- An adjustable cliff, allowing the golfer to tee-off from any height.
With all of these new features, the Gizmo can be used for an informal exploration of the factors affecting flight, or for an in-depth, quantitative physics lesson on projectile motion. Check out the Exploration Guide for more suggestions on how to approach this fundamental topic.
Of course, the one feature we didn't change was the sound clip of Gizmo inventor Raman Pfaff announcing, "Hole in one!"