Newton's Laws of Motion and Their Applications

Flashcards covering key vocabulary and concepts from the lecture on Newton's Laws of Motion and their applications, including definitions of various forces, laws, and related principles.

Newton's Laws of Motion

Fundamental principles governing the relationship between forces and the motion of objects, including their applications.

Force

A push or a pull that can cause an object to accelerate.

Resultant Force

The single force that has the same effect as all the individual forces acting on a body, found by vector addition.

Contact Forces

Forces that arise from physical contact between objects.

Non-Contact Forces

Forces that do not require physical contact, such as gravity and electrical forces.

Net Force

The vector sum of all forces acting on an object (ΣF).

Normal Force (FN)

A component of the contact force that a surface exerts on an object, which is perpendicular to the surface.

Frictional Force (f)

A contact force that opposes relative motion (or attempted motion) between two surfaces in contact and is parallel to the contact surface.

Tension (T)

The force exerted by strings, ropes, and wires when they are stretched tight, pulling the object to which it is attached.

Weight (W)

The force of Earth's gravitational attraction, which pulls an object toward the Earth's center (W = mg).

Mass (m)

A measure of the amount of 'stuff' contained in an object; an intrinsic property independent of its surroundings.

Force Resolution

The process of breaking down a force vector into its perpendicular components (Fx = F cosθ, Fy = F sinθ).

Pulley

A simple machine that redirects tension forces in ropes, transmitting them undiminished if massless and frictionless.

Hooke's Law

States that the force exerted by a spring is proportional to its length change from its natural unstretched length (F = -ks), where k is the spring constant.

Spring Constant (k)

A measure of the 'stiffness' of a spring, indicating the force required to stretch or compress it by a certain unit length.

Free-Body Diagram

A diagram that represents an object and all the external forces acting upon it, excluding forces the object exerts on its environment.

Newton's First Law of Motion

States that an object at rest remains at rest, and an object in motion continues in motion with constant velocity, unless acted upon by a net external force (also known as the Law of Inertia).

Inertia

The natural tendency of an object to resist a change in its state of motion (i.e., to remain at rest or continue moving at a constant speed in a straight line).

Inertial Frame of Reference

A reference frame in which Newton's First Law of Motion is valid; an unaccelerated frame.

Non-Inertial Frame of Reference

An accelerating reference frame where Newton's First Law of Motion is not directly valid without introducing fictitious forces.

Newton's Second Law of Motion

States that when a net external force (ΣF) acts on an object of mass (m), the acceleration (a) that results is directly proportional to the net force and inversely proportional to the mass (ΣF = ma).

Newton (N)

The SI unit of force, equivalent to kg·m/s².

Equilibrium

A state where the net force on an object is zero (ΣF = 0), resulting in zero acceleration, meaning the object is either at rest or moving with constant velocity.

Newton's Third Law of Motion

States that whenever one body exerts a force on a second body, the second body exerts an oppositely directed force of equal magnitude on the first body (FA on B = -FB on A).

Action-Reaction Pair

The two forces described by Newton's Third Law, which are equal in magnitude and opposite in direction, acting on different objects.

Static Friction (fs)

The frictional force that opposes the impending relative motion between two surfaces that are not sliding across one another, having a maximum value.

Coefficient of Static Friction (µs)

A dimensionless quantity that represents the ratio of the maximum static frictional force to the normal force (µs = fs,MAX / FN).

Kinetic Friction (fk)

The frictional force that opposes the relative sliding motion that actually occurs between two surfaces in contact.

Coefficient of Kinetic Friction (µk)

A dimensionless quantity that represents the ratio of the kinetic frictional force to the normal force (µk = fk / FN).