AP Physics 2 Lab Manual Overview

• Pressure is the force applied to a fluid per unit area.
• Gauge pressure is the absolute pressure minus the atmospheric pressure.
• Density is the mass per unit volume of a fluid.

3.C.4.1: Make claims about various contact forces between objects based on the microscopic cause of those forces.

3.C.4.2: Explain contact forces (tension, friction, normal, buoyant, spring) as arising from interatomic electric forces and that they therefore have certain directions.

• Newton's Second Law: the sum of the forces acting on an object is equal to the mass of the object multiplied by its acceleration.
• Free body diagrams and force vectors.

1.E.1.2: Select from experimental data the information necessary to determine the density of an object and/or compare densities of several objects.

3.C.4.2:Explain contact forces (tension, friction, normal, buoyant, spring) as arising from interatomic electric forces and that they therefore have certain directions.

• Kinetic energy, gravitational potential energy, and conservation of energy.
• Deriving equations of motion for projectiles

5.B.10.1: Make calculations related to a moving fluid using Bernoulli’s equation.

5.B.10.3: Make calculations related to a moving fluid using Bernoulli’s equation and the continuity equation.

5.B.10.4: Construct an explanation of Bernoulli’s equation in terms of the conservation of energy.

• The kinetic molecular theory describes gases as a large number of molecules in constant motion, colliding with each other and with the walls of their container.
• Gas pressure P is a measure of the average force F exerted by these collisions on a given area A of the container wall: $ P = F/A $.
• The first law of thermodynamics states that a change to the internal energy of a system is given by $ ∆U = Q + W $, where Q is the energy transferred to the system by heating and W is the work done on the system.
• The work done on a gas is defined by $ W = –P∆V $, where P is the pressure and ∆V is the change in volume.

5.B.7.2: Create a plot of pressure versus volume for a thermodynamic process from given data.

7.A.3.2: Design a plan for collecting data to determine the relationships between pressure, volume, and temperature, and/or the amount of an ideal gas; and to refine a scientific question proposing an incorrect relationship between the variables.

7.A.3.3: Analyze graphical representations of macroscopic variables for an ideal gas to determine the relationships between these variables and to ultimately determine the ideal gas law $ PV = nRT $.

• Specular reflection is the reflection of light from a smooth reflecting surface where the incident light and reflected light form the same angle relative to a line normal to the surface. This is also known as the Law of Reflection. Specular reflection assumes that the point at which each light ray is incident is perfectly flat and the normal line is perpendicular to the surface at that point.
• The difference between real images and virtual images formed by mirrors.
• Drawing ray diagrams using curved and flat mirrors.
• The spherical mirror equation and its variables.

6.E.4.1: Plan data collection strategies and perform data analysis and evaluation of evidence about the formation of images due to reflection of light from curved spherical mirrors.

6.E.4.2: Use quantitative and qualitative representations and models to analyze situations and solve problems about image formation occurring due to the reflection of light from surfaces.

• The index of refraction n of a transparent material is defined as the ratio of the speed of light in a vacuum c and the speed of light inside the transparent material v.
• Light crossing a boundary between two transparent materials will experience a direction change if the speed of light within those media is different. This is known as refraction, and can be quantified using the equation known as Snell’s law.

6.E.3.2: Plan data collection strategies as well as perform data analysis and evaluation of the evidence for finding the relationship between the angle of incidence and the angle of refraction for light crossing boundaries from one transparent material to another (Snell’s law).

6.E.3.3: Make claims and predictions about path changes for light traveling across a boundary from one transparent material to another at non-normal angles resulting from changes in the speed of propagation.

• Refraction: the path and speed of light change as the light crosses a boundary between two transparent media with dissimilar indices of refraction.
• Real images are formed by the convergence of light waves to produce a focused image visible on a screen.
• Virtual images are formed by the divergence of light rays and appear as if the image is spatially located behind the lens or mirror.
• The thin lens equation and its variables.

6.E.5.1: Use quantitative and qualitative representations and models to analyze situations and solve problems about image formation occurring due to the refraction of light through thin lenses.

6.E.5.2: Plan data collection strategies, perform data analysis and evaluation of evidence, and refine scientific questions about the formation of images due to refraction for thin lenses.

• Light demonstrates wave properties and can be quantified using characteristics such as wavelength and wave speed.
• A diffraction pattern can be observed as light waves pass through an opening whose dimensions are comparable to the wavelength.
• An interference pattern can be observed as light waves pass through a set of openings whose spacing is comparable to the wavelength.
• Both diffraction and interference are the result of constructive and destructive interference between coherent light waves as they occupy the same space at the same time.

6.C.3.1: Qualitatively apply the wave model to quantities that describe the generation of interference patterns to make predictions about interference patterns that form when waves pass through a set of openings whose spacing and widths are small compared with the wavelength of the waves.

• Electric fields are a useful way to model fundamental forces that can be exerted between charged objects at a distance without direct physical contact between the objects.
• Electric fields can be modeled using an array of vectors that indicate the direction and magnitude of the field at a given point in space.
• The electric potential difference (voltage) between two points in an electric field indicates the difference in electric potential energy per unit charge between the two points; the amount of energy (work) per unit charge required to move a charge from one point to the other.

2.E.2.1: Determine the structure of isolines of electric potential by constructing them in a given electric field.

• Magnetic fields are created by permanent magnets and current-carrying wires.
• A small magnet (such as the magnetized pointer in a compass) can be used to determine the direction of a magnetic field.

2.D.2.1: Create a verbal or visual representation of a magnetic field around a straight wire or a pair of parallel wires.

2.D.3.1: Describe the orientation of a magnetic dipole placed in a magnetic field in general and the particular cases of a compass in the magnetic field of Earth and iron filings surrounding a bar magnet.

2.D.4.1: Qualitatively analyze the magnetic behavior of a bar magnet composed of ferromagnetic material.

Students should be familiar with these concepts:

• Magnetic fields are created by permanent magnets and by current-carrying wires.
• Magnetic fields can be represented by magnetic field lines to visualize the strength and direction of the magnetic field.
• The magnetic field at the center of a current-carrying coil can be increased by adding additional loops to the coil.

2.D.2.1: Create a verbal or visual representation of a magnetic field around a straight wire or a pair of parallel wires.

• Electromotive force (emf) refers to the potential difference that causes charge to move (current) through a conducting material, like a wire. Emf is measured in units of volts.
• Magnetic flux Φ_B is a measure of the magnetic field B that passes through a given surface area A. It is often referred to as a measure of relative magnetic field strength and can be illustrated as the density of magnetic field lines that pass through a given surface area.

4.E.2.1: Predict which properties determine the motion of a simple harmonic oscillator and what the dependence of the motion is on those properties.Construct an explanation of the function of a simple electromagnetic device in which an induced emf is produced by a changing magnetic flux through an area defined by a current loop (i.e., a simple microphone or generator) or of the effect on behavior of a device in which an induced emf is produced by a constant magnetic field through a changing area.

• The difference between an electrical conductor and an insulator.
• Electric force and how electric charges interact.

4.E.4.2: Design a plan for the collection of data to determine the effect of changing the geometry and/or materials on the resistance or capacitance of a circuit element, and relate results to the basic properties of resistors and capacitors.

4.E.4.3: Analyze data to determine the effect of changing the geometry and/or materials on the resistance or capacitance of a circuit element, and relate results to the basic properties of resistors and capacitors.

• Series circuits are constructed by connecting components end-to-end, forming one path for current to flow.
• Parallel circuits are constructed by connecting each component to two common points, allowing multiple paths for current to flow.
• Capacitors are constructed of two parallel conductive plates separated by an insulator.
• Capacitors store charge when a potential difference is placed across the capacitor plates.

4.E.5.3: Plan data collection strategies and perform data analysis to examine the values of currents and potential differences in an electric circuit that is modified by changing or rearranging circuit elements, including sources of emf, resistors, and capacitors.

5.B.9.5: Describe and make predictions regarding electrical potential difference, charge, and current in steady state circuits composed of various combinations of resistors and capacitors using conservation of energy principles (Kirchhoff’s loop rule).

• Constructing circuits with components in series and parallel.
• Connecting a voltage sensor in parallel and a current sensor in series with the component being measured.
• Identifying resistor values using the color bands printed on the resistors.
• Resistors are used to control voltage and current, and capacitors are used to store electric charge.

4.E.5.1: Make and justify a quantitative prediction of the effect of a change in values or arrangements of one or two circuit elements on the currents and potential differences in a circuit containing a small number of sources of emf, resistors, capacitors, and switches in series and/or parallel.

4.E.5.2: Make and justify a qualitative prediction of the effect of a change in values or arrangements of one or two circuit elements on currents and potential differences in a circuit containing a small number of sources of emf, resistors, capacitors, and switches in series and/or parallel.

4.E.5.3: Plan data collection strategies and perform data analysis to examine the values of currents and potential differences in an electric circuit that is modified by changing or rearranging circuit elements, including sources of emf, resistors, and capacitors.

• Energy transfer occurs when photons are absorbed or emitted, for example, by atoms or nuclei.
• Light can be characterized as photons that each carry discrete energy $ E_{photon} $ proportional to their frequency $ f $.

6.F.3.1: Support the photon model of radiant energy with evidence provided by the photoelectric effect.

6.F.4.1: Select a model of radiant energy that is appropriate to the spatial or temporal scale of an interaction with matter.