AP Physics 1: Algebra-Based Flashcards: Motion of Orbiting Satellites
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 11 cards to help you master important concepts.
Under what condition is the motion of a central object in a two-body gravitational system considered negligible?
The central object’s motion is negligible when the orbiting satellite's mass is negligible in comparison to the central object’s mass.
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Under what condition is the motion of a central object in a two-body gravitational system considered negligible?
The central object’s motion is negligible when the orbiting satellite's mass is negligible in comparison to the central object’s mass.
How do two objects that interact only through gravitational forces move relative to each other?
The two objects move in orbits that are constrained by conservation laws, typically orbiting a common center of mass.
Define escape velocity.
Escape velocity is the minimum speed a satellite needs for the total mechanical energy of the satellite–central-object system to equal zero, allowing it to escape the gravitational pull.
What fundamental principles constrain the motion of orbiting satellites?
The motion of satellites in orbits is constrained by conservation laws, such as the conservation of energy and angular momentum.
What is the total mechanical energy of a system when a satellite achieves escape velocity?
When a satellite reaches escape velocity, the total mechanical energy of the satellite–central-object system is exactly equal to zero.
To send a probe to Mars permanently, what condition must be met regarding the probe-Earth system's mechanical energy upon launch?
The probe must be launched with at least escape velocity, meaning the total mechanical energy of the probe-Earth system must be equal to or greater than zero.
For a satellite in a stable circular orbit, which four key quantities of the system remain constant?
In a circular orbit, the system’s total mechanical energy, gravitational potential energy, and the satellite’s angular momentum and kinetic energy are all constant.
Why is the concept of a constant kinetic energy specific to circular orbits and not elliptical ones?
In a circular orbit, the satellite's distance from the central body and its speed are constant, keeping kinetic energy constant; in an elliptical orbit, both distance and speed vary.
What characterizes a two-object system where one object's motion is negligible?
This system is characterized by a massive central object and an orbiting satellite with a mass that is negligible in comparison to the central object’s mass.
A communications satellite maintains a perfect circular orbit around Earth. How do its kinetic and gravitational potential energies change over time?
They do not change; for a satellite in a circular orbit, both its kinetic energy and the system's gravitational potential energy are constant.
What is the relationship between escape velocity and the system's total mechanical energy?
Escape velocity is the specific speed that makes the satellite's kinetic energy large enough to exactly cancel out the system's negative gravitational potential energy, resulting in a total mechanical energy of zero.