Forces, Equilibrium, and Dynamics Lecture Review

This set of flashcards covers vocabulary and core concepts from the lecture including fluid mechanics, equilibrium, kinematics, Newton's laws, and momentum conservation.

Upthrust

The force experienced by an object which is fully or partially submerged in a liquid due to a pressure difference.

Fluid Pressure

The pressure in liquids and gases calculated using the formula $\Delta P = \rho g h$, where $\rho$ is density, $g$ is acceleration due to gravity ($9.81\,m/s^2$), and $h$ is the depth below the liquid surface.

Equilibrium

An object is in this state if the net force is equal to zero and the net moment is equal to zero.

Couple

Two parallel forces of equal magnitude acting at two different points in opposite directions.

Torque of a couple

The product of force and the perpendicular distance between the lines of action of both forces.

Kinematics

The study of moving objects without reference to the force causing the movement.

Rest

The state when an object does not change its position with respect to its surroundings.

Motion

The state when an object changes its position with respect to its surroundings.

Distance

The total length of a path ($s$) measured in meters ($m$).

Displacement

The shortest directed distance ($s$) between two points, measured in meters ($m$).

Speed

The distance covered by an object per unit time.

Uniform speed

When an object covers equal distance in equal intervals of time.

Velocity

The change of displacement per unit time.

Acceleration

The gradient of a velocity-time graph, representing the rate of change of velocity.

Free fall motion

Motion of an object under the action of gravity in a vertical line with no opposing force or air resistance.

Projectile motion

Two-dimensional motion of an object on a curved path, characterized by having both horizontal and vertical components of velocity.

Newton's Second Law of Motion

A mathematical relationship stating that the resultant force ($F_{net}$) is responsible for producing acceleration ($a$), where $F_{net} = ma$.

Terminal velocity

The maximum constant velocity maintained when the drag force ($F_D$) becomes equal in magnitude to the weight ($W$) of the object.

Momentum

A vector quantity defined as the product of mass ($m$) and velocity ($v$).

Newton's Third Law of Motion

The law stating that every action has an equal and opposite reaction; if object A exerts a force on object B, object B exerts a force of equal magnitude and opposite direction on object A.

Law of conservation of momentum

For an isolated system with no external force, the total momentum of the system before any change is equal to the total momentum of the system after the change.