orbital motion

    Cards (14)

    • An artificial satellite is a man-made body placed in orbit around the earth or another planet to collect information about it or communicate. The International Space Station is an example of an artificial satellite.
    • Artificial satellites orbiting the Earth are a familiar part of modern technology.
    • A circular orbit is the simplest case. Circular orbital motion is when an object moves in a circular path around the center of mass of a system.
    • The only force acting on a satellite in a circular orbit around the earth is the earth’s gravitational attraction, which is directed toward the center of the earth and hence toward the center of the orbit.
    • This means that the satellite is in uniform circular motion and its speed is constant.
    • The satellite isn’t falling toward the earth; rather, it’s constantly falling around the earth. In a circular orbit, the speed is just right to keep the distance from the satellite to the center of the earth constant.
    • In a circular orbit, the following quantities are constant: distance, speed, angular speed, and potential and kinetic energy.
    • Earth’s actual: Mass = 5.972x10^24 kgs radius = 6.38 x10^6 m
    • Gravitational force. Note: Fg = Fc (centripetal force) Fg = G Mm / r^2 where; Fg = gravitational force G = gravitational constant M = mass of the Earth m = mass of the satellite
    • Radial acceleration -acceleration of the satellite arad = mv^2 / r where; arad = radial acceleration m = mass v = velocity r = radius
    • Formula = arad Note: (m) or mass in the a rad equation will be diminished or removed because the orbital motion of the satellite does not depend on its mass.
    • v= √Gm/r
      This relationship shows that we can’t choose the orbit radius r and the speed independently; for a given radius r, the speed for a circular orbit is determined
    • The satellite’s mass (m) doesn’t appear in the equation above, which shows that the motion of a satellite does not depend on its mass. If we could cut a satellite in half without changing its speed, each half would continue on with the original motion.
    • T = 2πr/v
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