PhysicsQ&A by dot point

Define electric current, voltage, and resistance, and use Ohm's law V = IR to relate them in a simple circuit (MA STE Introductory Physics, electric circuits).

Describe positive and negative charge and that like charges repel and unlike charges attract, and use Coulomb's law qualitatively (force proportional to the charges and inversely proportional to the square of the distance) (MA STE Introductory Physics, Motion and Forces, HS-PS2-4).

Define electrical power as the rate at which a circuit transfers energy, use P = IV (and energy E = Pt), and connect electrical power to the transformation of electrical energy into other forms (MA STE Introductory Physics, electric circuits, Energy).

Explain electromagnetic induction (a changing magnetic field produces a current in a conductor) and how a generator converts kinetic energy into electrical energy (MA STE Introductory Physics, Motion and Forces, Energy, HS-PS2-5, HS-PS3-5).

Describe magnetic poles and fields, state that like poles repel and unlike poles attract, and explain that an electric current produces a magnetic field (the basis of electromagnets) (MA STE Introductory Physics, Motion and Forces, HS-PS2-5).

Compare series and parallel circuits: in series the current is the same and voltage divides; in parallel the voltage is the same and current divides, and adding parallel branches lowers the total resistance (MA STE Introductory Physics, electric circuits).

State the law of conservation of energy, apply it to mechanical systems by setting the energy before equal to the energy after, and account for energy transformed into thermal energy (MA STE Introductory Physics, Energy, HS-PS3-1, HS-PS3-2).

Describe how devices convert energy from one form into another, define efficiency as useful output over total input, and explain why some energy is always transformed into unwanted thermal energy (MA STE Introductory Physics, Energy, HS-PS3-3).

Model two objects interacting through a gravitational, electric, or magnetic field, and describe how the energy stored in the field changes as the objects move closer or farther apart (MA STE Introductory Physics, Energy, HS-PS3-5).

Define kinetic energy as the energy of motion (KE = 1/2 mv^2) and gravitational potential energy as the energy of position (PE = mgh), and calculate each (MA STE Introductory Physics, Energy, HS-PS3-1, HS-PS3-2).

Describe thermal energy as the energy of particle motion, state that heat flows spontaneously from hotter to colder regions (the second law), and calculate heat using Q = mc(delta-T) (MA STE Introductory Physics, Energy, HS-PS3-2, HS-PS3-4).

Define work as a force acting through a distance (W = Fd), define power as the rate of doing work (P = W/t), and apply both to everyday situations (MA STE Introductory Physics, Energy, HS-PS3-1).

Draw free-body diagrams showing all forces acting on an object, and use them to identify equilibrium (zero net force) and to find the net force in one direction (MA STE Introductory Physics, Motion and Forces).

Describe Newton's law of gravitation and Coulomb's law, and use proportional reasoning to predict how the gravitational and electric forces change with mass, charge, and distance (MA STE Introductory Physics, HS-PS2-4).

State Newton's first law, explain inertia as the resistance to a change in motion, and identify the role of balanced and unbalanced (net) forces (MA STE Introductory Physics, Motion and Forces).

State and apply Newton's second law, F = ma, to calculate net force, mass, or acceleration, finding the net force first in multi-force situations (MA STE Introductory Physics, HS-PS2-1).

State Newton's third law, identify action-reaction force pairs, and explain why the two forces in a pair act on different objects and therefore do not cancel (MA STE Introductory Physics, Motion and Forces).

Distinguish weight from mass, calculate weight using Fg = mg, and describe the normal force and friction as the contact forces that act on objects on a surface (MA STE Introductory Physics, Motion and Forces).

Define and calculate displacement, average velocity, and acceleration, and distinguish each from the everyday words distance and speed (MA STE Introductory Physics, Motion and Forces).

Analyze free fall as motion with constant acceleration g, using the kinematic equations to find fall time, speed, or height, and explain why mass does not affect the rate of fall (MA STE Introductory Physics, Motion and Forces).

Interpret and sketch position-time and velocity-time graphs, reading slope as velocity or acceleration and area under a velocity-time graph as displacement (MA STE Introductory Physics, Motion and Forces).

Describe projectile motion as independent horizontal (constant velocity) and vertical (free fall) motions, and explain why a horizontally launched and a dropped object reach the ground together (MA STE Introductory Physics, Motion and Forces).

Distinguish scalar from vector quantities, use SI units and the metric prefixes, and convert measurements before substituting them into an equation (MA STE Introductory Physics, Motion and Forces).

Use the constant-acceleration (kinematic) equations from the reference sheet to solve for an unknown displacement, velocity, acceleration, or time in straight-line motion (MA STE Introductory Physics, Motion and Forces).

Explain that circular motion requires a net force directed toward the center (a centripetal force), and identify the real force providing it in everyday examples (MA STE Introductory Physics, Motion and Forces).

Distinguish elastic from inelastic collisions, explain that momentum is conserved in both while kinetic energy is conserved only in elastic collisions, and analyze recoil and explosion situations (MA STE Introductory Physics, Motion and Forces).

State the law of conservation of momentum and use it to calculate an unknown velocity after a collision when no external force acts (MA STE Introductory Physics, HS-PS2-2).

Apply science and engineering ideas to explain how a device that extends the time of a collision reduces the force on an object, and evaluate a safety design (MA STE Introductory Physics, HS-PS2-3).

Define momentum as p = mv, define impulse as a force acting over a time, and relate impulse to the change in momentum (MA STE Introductory Physics, Motion and Forces).

Describe sound as a longitudinal wave that needs a medium, relate its frequency to pitch and its amplitude to loudness, and describe how its speed depends on the medium (MA STE Introductory Physics, Waves, HS-PS4-1).

Describe the electromagnetic spectrum as a range of waves with different wavelengths, frequencies, and energies, order its regions, and explain how devices use waves to transmit information (MA STE Introductory Physics, Waves, HS-PS4-3, HS-PS4-5).

Distinguish transverse waves (particle motion perpendicular to the wave direction) from longitudinal waves (particle motion parallel to the wave direction), and classify examples such as light, water, and sound waves (MA STE Introductory Physics, Waves, HS-PS4-1).

Describe what happens when a wave meets a boundary: reflection, refraction, transmission, and absorption, with examples for light and sound (MA STE Introductory Physics, Waves, HS-PS4-1).

Define wavelength, frequency, period, and amplitude, and use the wave equation v = f(lambda) to relate the speed, frequency, and wavelength of a wave (MA STE Introductory Physics, Waves, HS-PS4-1).