SvS Biology and Junior Science
a) The trebuchet was one of the most devastating weapons of the Middle Ages. During medieval sieges, this destruction machine crushed castle walls. Using trial and error, medieval engineers adjusted the trebuchet to make sure its missile hit the castle wall--and destroyed it. NOVA's science game, "Destroy the Castle," is very much like the real thing. There are five elements you can adjust in your trebuchet:
stone ball weight
sling length
counterweight design
distance from the castle
whether to add wheels
Build it right, and you will crush the wall. Build it wrong, though, and you may have to face some painful consequences.
Play Destroy the Castle - don't forget to read other information associated with it and see how it all works.
b) The mission of a World War II submarine was usually pretty straightforward: seek out and destroy enemy vessels. To carry out the mission, the submarine relied on the automobile torpedo, a 3,000-pound, 18-foot-long, self-propelled missile consisting of 3,000 precision-built parts.
How a Torpedo Works reveals the inner workings of a torpedo and how a gyroscope and pendulum control its path through the water. Firing Procedure puts you in the role of skipper in a Gato-class U.S. submarine and explains, step by step, what you need to do to aim your torpedo at an enemy ship. Sink the Ship lets you be the specialist in a submarine's torpedo room who is in charge of setting torpedo gyroscopes.
How a Torpedo Works
Firing Procedure
Sink the Ship
c) Picture this: A young Galileo stands high up in the famous Leaning Tower of Pisa. He is in the middle of a famous experiment -- the one in which he proves, by dropping cannonballs of different weights, that all objects fall at the same rate. It's the kind of story that's easy to imagine, easy to remember. Truth is, it may never have happened.
Still, Galileo did conduct some ingenious experiments on gravity while at Pisa. In fact, for his approach to science -- that of using math in analyzing the results of experiments -- he is credited for initiating the modern style of scientific research. The "thought experiment" -- a virtual experiment carried out by the mind using reasoning and logic -- was another device the 16th-century scientist used to great advantage.
We'll get a taste of Galileo's virtual thought experiments, and we'll conduct one of his actual experiments, virtually. Ready to begin? Then let's start with Experiment #1...
Experiment 1
Experiment 2
Experiment 3
d) Vectors - Motion and Forces in Two Dimensions
Vector principles and operations are introduced and combined with kinematic principles and Newton's laws to describe, explain and analyze the motion of objects in two dimensions. Applications include riverboat problems, projectiles, inclined planes, and static equilibrium.
Lesson 1: Vectors - Fundamentals and Operations
Lesson 2: Projectile Motion
Lesson 3: Forces in Two Dimensions
e) Information for you: During a typical trip to school, your car will undergo a series of changes in its speed. If you were to inspect the speedometer readings at regular intervals, you would notice that it changes often. The speedometer of a car reveals information about the instantaneous speed of your car; that is, it shows your speed at a particular instant in time.
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S. van Strien
