IB Sports, exercise and health science B.2.1 Newton’s Laws of Motion Key Definitions

Acceleration is the rate of change of velocity over time.

Angular acceleration is the rate at which angular velocity changes over time.

Angular displacement refers to the change in the angular position of a rotating body.

Angular momentum measures the amount of rotational motion an object has or can achieve.

The motion of a body about a fixed point or fixed axis

Angular velocity measures the rate at which an object rotates around an axis.

A number that measures how much friction exists between two surfaces. It's also a measure of how much force is required to move an object across a surface

A collision occurs when two or more objects come into contact and exert forces on each other over a short period of time.

Conservation of angular momentum is a physical property of a spinning system such that its spin remains constant unless it is acted upon by an external torque

Coordinates measure distance from an origin (e.g., in meters) and are given in two dimensions (x, y: horizontal and vertical) or three dimensions (x, y, z: horizontal, vertical, lateral). Two systems for three-dimensional coordinates: System 1: x = horizontal, y = vertical, z = lateral and System 2: x = horizontal, y = lateral, z = vertical. Angular coordinates are measured as angles around one or more axes.

Displacement is the shortest straight-line distance between an object’s starting and ending positions, including direction.

Distance is the total length of the path traveled by an object, regardless of direction.

Dynamic friction is the force that resists the motion of an object that is already moving. It's also known as kinetic friction.

The ability to do work, which is the ability to exert a force causing displacement of an object.

A force that opposes the motion between two surfaces in contact, acting parallel to the surfaces and in the opposite direction of motion.

An attractive force that acts between objects with mass. Proportional to mass, inversely proportional to the square of the distance. Effects of Gravity: Causes planetary orbits and is responsible for the Earth’s attraction to objects near its surface.

Impulse is the product of force and the time.

The product of force and time (F×Δt), representing the change in momentum.

Inertia is a property of matter that causes an object to resist changes in its state of motion. The more mass an object has, the greater its inertia.

Instantaneous acceleration is the rate of change of velocity at a specific instant in time.

Velocity measured over an extremely short time interval ("instant").

Kinematics is the branch of mechanics that studies motion without considering the forces that cause it. It focuses on describing motion using parameters such as position, displacement, speed, velocity, and acceleration.

Force applied over a period of time. Formula: J=FΔt where: FF = force (N) and ΔtΔt = time duration (s). Also a vector quantity.

Property of an object due to its movement. Formula: p=mv, where: mm = mass (kg) and vv = velocity (m/s). Vector quantity (has both size and direction). Measured in kg·m/s.