AP®︎ Physics 1: Topic 3.3 Practice Test

Essential Knowledge: 3.3.A.1

A system composed of two or more objects has potential energy if the objects within that system only interact with each other through conservative forces.

Essential Knowledge: 3.3.A.2

Potential energy is a scalar quantity associated with the position of objects within a system.

Essential Knowledge: 3.3.A.3

The definition of zero potential energy for a given system is a decision made by the observer considering the situation to simplify or otherwise assist in analysis.

Essential Knowledge: 3.3.A.4

The potential energy of common physical systems can be described using the physical properties of that system.

Essential Knowledge: 3.3.A.4.i

The elastic potential energy of an ideal spring is given by the following equation, where $\Delta x$ is the distance the spring has been stretched or compressed from its equilibrium length. Relevant equation: $U_s = \frac{1}{2}k(\Delta x)^2$

Essential Knowledge: 3.3.A.4.ii

The general form for the gravitational potential energy of a system consisting of two approximately spherical distributions of mass (e.g., moons, planets or stars) is given by the equation $U_g = -G\frac{m_1m_2}{r}$

Essential Knowledge: 3.3.A.4.iii

Because the gravitational field near the surface of a planet is nearly constant, the change in gravitational potential energy in a system consisting of an object with mass $m$ and a planet with gravitational field of magnitude $g$ when the object is near the surface of the planet may be approximated by the equation $\Delta U_g = mg\Delta y$.

Essential Knowledge: 3.3.A.5

The total potential energy of a system containing more than two objects is the sum of the potential energy of each pair of objects within the system.