Motion, Energy and Gravity

These flashcards cover key vocabulary terms and definitions related to motion, gravity, and energy, as discussed in the lecture.

Mass

The amount of matter in an object.

Weight

The force that acts upon an object due to gravity.

Speed

The rate at which an object moves.

Velocity

Speed in a specific direction.

Acceleration

Any change in velocity, measured in m/s².

Newton's 1st Law of Motion

An object moving at constant velocity remains at constant velocity unless acted upon by a net force.

Newton's 2nd Law of Motion

Force equals mass times acceleration (F = ma).

Newton's 3rd Law of Motion

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

Gravitational acceleration

The acceleration of an object due to gravity, approximately 9.8 m/s² on Earth.

Universal Law of Gravitation

Every mass attracts every other mass, with attraction proportional to the product of their masses and inversely proportional to the square of their distance (between centers).

Orbital Path

The trajectory an object follows around another object in space.

Tides

The rise and fall of sea levels caused by the gravitational forces of the Moon and Sun.

Spring Tides

Higher high tides occurring near the full and new moon when the gravitational forces of the Moon and Sun align.

Neap Tides

Lower high tides occurring during the first and third quarters of the moon.

Conservation of Angular Momentum

An object's angular momentum remains constant unless acted upon by an external force.

Escape Velocity

The minimum velocity needed for an object to break free from the gravitational attraction of a celestial body.

1 AU

1.5 × 108 kilometers (or about 93 million miles), which is the average distance from the Earth to the Sun.

Ptolemaic Model

An astronomical model that places Earth at the center of the universe, with planets and the Sun moving in perfect circular orbits around it.

Conservation of Angular Momentum

in a closed system, the angular momentum remains constant if no external torque acts on it. If not,

The Dart Mission

Conservation of Mass Energy

the total mass and energy of an isolated system remains constant over time, regardless of the processes occurring within that system.

Escape Velocity

escape velocity is the velocity required to escape an astronomical body

Calculating Escape Velocity

V _e = (2GM/r)^0.5

Angular Momentum

mass x velocity x radius

Momentum

mass x velocity