What is the law of universal gravitation? Using Kepler’s laws, Sir Isaac Newton became the first scientist to mathematically describe how the force of gravity behaves. He reasoned that gravity is the force that accounts for both the fall of an apple from a tree and the movement of the moon around Earth. In 1687, Newton formulated the law of universal gravitation. The law of universal gravitation states that all objects in the universe attract each other through gravitational force. The strength of this depends on the product of the masses of the objects. Gravitational force is also inversely proportional to the square of the distance between the objects. How does gravity affect planetary motion? If a ball is attached to a string and is swung around, it moves in a circular path. The inward force that causes an object to move in a circular path is called centripetal force. If the string breaks, the ball will move off in a straight line. When the string is intact, the centripetal force prevents the ball from flying off. When planets orbit the sun, a force similar to centripetal force prevents them from moving out of their orbits and into a straight line. The sun’s gravity is the that keeps the planets moving in orbit around the sun. Collapse How did the solar system form? The formation of the solar system is thought to have begun 4.6 billion years ago when a cloud of gas and dust collapsed. This kind of cloud, from which solar systems form, is called a solar nebula. In a solar nebula, the inward pull of gravity is balanced by the outward push of gas pressure in the cloud. Scientists think that an outside force, perhaps the explosion of a nearby star, caused the nebula to compress and contract under its own gravity. The solar system formed in a single region of the nebula, perhaps several light-years across. The sun probably formed from a region that had a mass that was slightly greater than today’s mass of the sun and planets. As a region of the solar nebula collapsed, gravity pulled most of the mass toward the center of the nebula. As the nebula contracted, it began to rotate with increasing speed and flattened out into a disk.
What is the law of universal gravitation? Using Kepler’s laws, Sir Isaac Newton became the first scientist to mathematically describe how the force of gravity behaves. He reasoned that gravity is the force that accounts for both the fall of an apple from a tree and the movement of the moon around Earth. In 1687, Newton formulated the law of universal gravitation. The law of universal gravitation states that all objects in the universe attract each other through gravitational force. The strength of this depends on the product of the masses of the objects. Gravitational force is also inversely proportional to the square of the distance between the objects. How does gravity affect planetary motion? If a ball is attached to a string and is swung around, it moves in a circular path. The inward force that causes an object to move in a circular path is called centripetal force. If the string breaks, the ball will move off in a straight line. When the string is intact, the centripetal force prevents the ball from flying off. When planets orbit the sun, a force similar to centripetal force prevents them from moving out of their orbits and into a straight line. The sun’s gravity is the that keeps the planets moving in orbit around the sun. Collapse How did the solar system form? The formation of the solar system is thought to have begun 4.6 billion years ago when a cloud of gas and dust collapsed. This kind of cloud, from which solar systems form, is called a solar nebula. In a solar nebula, the inward pull of gravity is balanced by the outward push of gas pressure in the cloud. Scientists think that an outside force, perhaps the explosion of a nearby star, caused the nebula to compress and contract under its own gravity. The solar system formed in a single region of the nebula, perhaps several light-years across. The sun probably formed from a region that had a mass that was slightly greater than today’s mass of the sun and planets. As a region of the solar nebula collapsed, gravity pulled most of the mass toward the center of the nebula. As the nebula contracted, it began to rotate with increasing speed and flattened out into a disk.
Unit%202%20%20Lesson%202%20%20Gravity%20and%20the%20Solar%20System%20Power%20Notes%20Outline.docx