AP Physics C: Mechanics Flashcards: Potential Energy
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.
State the integral equation that relates the change in potential energy (ΔU) to a conservative force.
The relationship is given by the equation ΔU = -∫ₐᵇ F⃗ₑₓ(r) ⋅ dr⃗.
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State the integral equation that relates the change in potential energy (ΔU) to a conservative force.
The relationship is given by the equation ΔU = -∫ₐᵇ F⃗ₑₓ(r) ⋅ dr⃗.
Why is the general form of gravitational potential energy (U₉ = -Gm₁m₂/r) a negative value?
It is negative by convention, setting the potential energy to zero when the two masses are infinitely far apart (r=∞).
What is elastic potential energy?
Elastic potential energy is the energy stored in an ideal spring due to its compression or extension from its equilibrium position.
What is the equation for the conservative force in the x-direction (Fₓ) derived from its potential energy function U(x)?
The equation is Fₓ = -dU(x)/dx.
Using Fₓ = -dU(x)/dx, find the force associated with the elastic potential energy Uₛ = ½k(Δx)².
Taking the derivative gives Fₓ = -d/dx(½kx²) = -kx, which is the equation for the restoring force of a spring (Hooke's Law).
State the general equation for the gravitational potential energy (U₉) of a system of two masses.
The equation is U₉ = -Gm₁m₂/r, where G is the gravitational constant and r is the distance between the centers of mass.
In one dimension, how can the conservative force be determined from the potential energy function U(x)?
The conservative force is the negative of the slope (the derivative) of the system's potential energy with respect to its position.
How is the change in a system's potential energy (ΔU) related to the work done by a conservative force?
The change in potential energy is the negative of the work done by the conservative force, as defined by the integral of the force over a path.
What is the equation for the elastic potential energy (Uₛ) of an ideal spring?
The elastic potential energy is given by Uₛ = ½k(Δx)², where k is the spring constant and Δx is the displacement from equilibrium.
What system does the general form of the gravitational potential energy equation describe?
It describes the potential energy of a system consisting of two approximately spherical distributions of mass.
What is the potential energy of a system?
Potential energy is the energy associated with the configuration of a system of objects that exert forces on each other.