Physics: Dynamics

Dynamics in Physics

The foundation of dynamics in physics is Newton’s Laws of Motion.
Newton’s First Law, also known as the Law of Inertia states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force.
Newton’s Second Law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass, often summarised by the formula F = ma.
Newton’s Third Law, the law of action and reaction, states that for every action, there is an equal and opposite reaction.

Force is described as any interaction that changes the motion of an object. These can be either contact forces such as friction and tension, or non-contact forces like gravity and magnetism.
Mass is a measure of the amount of matter in an object. It’s a scalar quantity, meaning it only has magnitude and no direction, and is usually measured in kilograms (kg).

Friction is the resistive force that opposes the motion or attempted motion of an object either past each other or past a stationary barrier.
Air resistance or drag is a type of friction that acts against the direction of motion when an object moves through air.

Gravitational force is the force that attracts two bodies towards each other; it is directly proportional to the product of their masses and inversely proportional to the square of the distance between them as defined by Newton’s Law of Universal Gravitation.
On the surface of the Earth, gravity gives weight to physical objects providing the force behind the phenomenon of weight.

Momentum is defined as the product of the mass and velocity of an object, and like velocity, it is a vector quantity with both magnitude and direction.
The law of conservation of momentum states that the total linear momentum in a closed system is constant, providing no external forces are acting.

Work is defined as the measure of energy transfer that occurs when an object is moved due to an applied force along a displacement.
Energy is the capacity of a physical system to perform work, often categorised as kinetic energy and potential energy.
Power in physics is the amount of energy transferred or converted per unit time; it’s measured in watts, where one watt equals one joule per second.