HL IB Physics Forces & Momentum

Vocabulary flashcards for HL IB Physics Forces & Momentum.

Free-Body Diagram

Diagrams used to simplify situations with multiple forces acting on objects, showing forces, directions, and magnitudes.

Resultant Force

The vector sum of all forces acting on a body, determining the change in the object's motion.

Balanced Forces

Forces that combine in such a way that they cancel each other out, resulting in a net force of zero.

Newton's First Law

A body will remain at rest or move with constant velocity unless acted on by a resultant force.

Newton's Second Law

The resultant force on an object is directly proportional to its acceleration: F = ma.

Newton's Third Law

If Object A exerts a force on Object B, then Object B will exert a force on Object A which is equal in magnitude but opposite in direction.

Contact Force

A force which acts between objects that are physically touching, such as friction, fluid resistance, tension, and normal force.

Non-Contact Force

A force which acts at a distance without physical contact, such as gravitational, electrostatic, and magnetic forces.

Frictional Force

A force that opposes the motion of an object, slowing it down and transferring energy by heating.

Static Friction

Friction that occurs when a body is stationary on a surface.

Dynamic Friction

Friction that occurs when a body is in motion on a surface.

Hooke's Law

The extension of a material is directly proportional to the applied force up to the limit of proportionality: F = -kx.

Viscous Drag

The frictional force between an object and a fluid which opposes the motion between the object and the fluid.

Stoke's Law

Friction force on small spherical object moving through a viscous fluid. It is given by: F_d = 6πηrv.

Buoyancy

The upward force exerted on a body immersed in a fluid, equal to the weight of the fluid displaced.

Linear Momentum

The product of an object's mass and velocity: p = mv.

Conservation of Linear Momentum

The total linear momentum before a collision equals the total linear momentum after a collision, unless acted on by a resultant external force.

Impulse

The product of the force applied and the time for which it acts, equal to the change in momentum: J = FΔt = Δp.

Elastic Collision

A collision in which kinetic energy is conserved.

Inelastic Collision

A collision in which kinetic energy is not conserved.

Angular Displacement

The change in angle, in radians, of a body as it rotates around a circle.

Angular Speed

The rate of change of angular displacement with respect to time.

Centripetal Force

The resultant force perpendicular to the velocity required to keep a body in a uniform circular motion, acting towards the center of the circle.

Centripetal Acceleration

The acceleration of an object towards the center of a circle when the object is rotating around the circle at a constant speed.