Table of Contents
Is energy conserved in planetary orbits?
For a planet of mass m in an elliptical orbit, conservation of angular momentum implies that as the object moves closer to the sun it speeds up. Both energy conservation and angular momentum conservation are important to planetary orbits.
How do you explain a planetary motion?
Three laws devised by Johannes Kepler to define the mechanics of planetary motion. The first law states that planets move in an elliptical orbit, with the Sun being one focus of the ellipse. This law identifies that the distance between the Sun and Earth is constantly changing as the Earth goes around its orbit.
Do planets have potential energy?
Gravitational potential energy is stored energy subject to gravitational attraction by another body. As a planet nears the sun, its gravitational energy decreases, but its kinetic energy increases. However, the sum of the gravitational potential energy and kinetic energy is always constant along its orbit.
What is constant for planetary motion?
Kepler’s second law states that a planet sweeps out equal areas in equal times, that is, the area divided by time, called the areal velocity, is constant.
Is any energy consumed in planetary motion?
No energy is consumed in the planetary motion because in planetary motion work done by the planet in moving the circular motion is zero. The earth moving round the sun in an orbit is acted upon by a force; hence work must be done on the earth by this force.
Why is energy conserved in orbit?
The acceleration due to gravity changes as we move away from Earth, and the expression for gravitational potential energy must reflect this change. The total energy of a system is the sum of kinetic and gravitational potential energy, and this total energy is conserved in orbital motion.
Why is planetary motion elliptical?
The orbit of an object around its ‘parent’ is a balance between the force of gravity and the object’s desire to move in a straight line. Hence, the object’s distance from its parent oscillates, resulting in an elliptical orbit.
What are the 3 laws of planetary motion?
There are actually three, Kepler’s laws that is, of planetary motion: 1) every planet’s orbit is an ellipse with the Sun at a focus; 2) a line joining the Sun and a planet sweeps out equal areas in equal times; and 3) the square of a planet’s orbital period is proportional to the cube of the semi-major axis of its …
Which planet has most energy?
The planet that shines the most, relative to its size, is Saturn, but Jupiter and Neptune also radiate significantly more energy than they receive. Uranus, an odd planet in many ways, shines the least of all the solar system’s outer worlds, emitting about as much energy as Earth.
How do the planets move according to Kepler’s law of planetary motion?
Kepler’s first law means that planets move around the Sun in elliptical orbits. An ellipse is a shape that resembles a flattened circle. How much the circle is flattened is expressed by its eccentricity. Read more about planetary orbit.
Which of the following quantities are not constant in a planetary motion?
EXPLANATION: The speed in an elliptical orbit is not constant and hence not the kinetic energy.