Galileo Drops the Ball - Virtual Experiment
In around 1590 Galileo Galilei (1564-1642) climbed up the Leaning Tower of Pisa and dropped some balls to the ground. Two balls of different masses, but of similar shape and density that were released together hit the ground at the same time. Until then it was commonly believed that heavy things fall faster than light things. Many people still believe this, and casual observation of everyday phenomena often does tend to confirm this view. If you drop a brick and a feather at the same time the brick will probably hit the ground first. But this is because of differences in the amount of friction between these objects and the air around them, not because their masses are different. Galileo’s discovery is important in understanding how parachutes work. Click on the image to the left to try Galileo’s experiment for yourself. Find out more about Galileo Galilei.
Planet Facts: Interesting Facts about the Eight Planets
Order of the planets The order of planets from closest to farthest from the Sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The largest planet is Jupiter, followed by Saturn, Uranus, Neptune, Earth, Venus, Mars and, the smallest planet, Mercury. If you include dwarf planets as well, the planets in order becomes Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Haumea, Makemake and Eris being the furthest from the Sun. Distance of the planets from the Sun For the distances between each of the planets, see our distances between planets calculator. You can also calculate your weight on other planets. Types of planets The planets fall into two categories based on their physical characteristics: the terrestrial planets and the gas giants. Planet facts Click any of the eight planets below to find out more about the remarkable objects in our solar system. What is a planet? The answer to this question is a highly controversial one.
Acceleration - Physics for Kids!
Acceleration is a way to measure how fast something is speeding up. Suppose you are riding your bike. You start out going very slowly, hardly pedaling at all. Now you begin to pedal as hard as you can, to speed up - you are accelerating. Now that you are going at a normal speed, you stop pedaling so hard, and just pedal normally. If you stop pedaling now, friction will work on your bike tires (and you'll have friction from the air, too), and you'll soon start to go slower. One important cause of acceleration is gravity. The acceleration of Earth's gravity will speed you up at about 9.8 meters per second per second (9.8 m/s2, or 9.8 meters per second squared). Standing on the cliff before you jump, you're going zero meters/second. You can use acceleration to find out the mass of an object, because force = mass x acceleration. Learn by doing - Using bikes to work with the physics of motion To find out more about acceleration, check out these books from Amazon.com or from your library: or
Motion: Introduction
Motion is one of the key topics in physics. Everything in the universe moves. It might only be a small amount of movement and very very slow, but movement does happen. Acceleration is a twist on the idea of velocity. There are two main ideas when you study mechanics. There are also more complex movements when an object's direction is changing. In order to really understand motion, you have to think about forces, acceleration, energy, work, and mass. Or search the sites for a specific topic.
