Physics Concepts on Motion and Forces

Vocabulary flashcards covering key physics concepts related to motion, forces, and gravitational laws.

Terminal Velocity

Constant speed reached when air resistance equals gravity.

Newton

's 3rd Law

For every action, there is an equal and opposite reaction.

Kepler

's 1st Law

Planet orbits are ellipses.

Kepler

's 2nd Law

Planets sweep equal area in equal time; faster when closer to the Sun.

Kepler

's 3rd Law

Period squared equals distance cubed: T^2 = D^3. (Further planets take longer)

Newton

's Universal Law of Gravitation

Gravitational force is proportional to mass and inversely proportional to the distance squared (F \propto M1 M2 / r^2).

F1→2 and F2→1 in a collision

Forces are equal and opposite (F{1 \to 2} = F{2 \to 1}).

Scale reading in an elevator (constant velocity)

Reads true weight.

Scale reading in an elevator (increasing velocity up)

Reads more than true weight (feels heavier).

Scale reading in an elevator (decreasing velocity up)

Reads less than true weight (feels lighter).

Scale reading in an elevator (constant velocity down)

Reads true weight.

Scale reading in an elevator (increasing velocity down)

Reads less than true weight (feels lighter).

Scale reading in an elevator (decreasing velocity down)

Reads more than true weight (feels heavier).