Physics: Forces and Types

Definition of Force

• A force is a push or pull that causes an object to change its motion or shape
• It is a vector quantity, having both magnitude (amount of force) and direction

Types of Forces

• Contact Forces: Forces that arise from physical contact between two objects, e.g.
  • Frictional force (resists motion between two surfaces in contact)
  • Normal force (perpendicular force exerted by a surface on an object)
  • Tension force (force exerted by a stretched string or wire)
• Non-Contact Forces: Forces that act over a distance, without physical contact, e.g.
  • Gravity (force of attraction between two objects with mass)
  • Electromagnetic forces (forces between charged particles or magnets)
  • Nuclear forces (forces that hold quarks together inside protons and neutrons)

Characteristics of Forces

• Magnitude: The amount of force, measured in units of Newtons (N)
• Direction: The direction in which the force is applied
• Resultant Force: The net force acting on an object, resulting from multiple forces acting simultaneously
• Equilibrium: A state in which the net force on an object is zero, resulting in no acceleration

Newton's Laws of Motion

• First Law (Law of Inertia): An object at rest remains at rest, and an object in motion remains in motion, unless acted upon by an external force
• Second Law (F = ma): The force applied to an object is equal to the mass of the object multiplied by its acceleration
• Third Law (Action and Reaction): For every action, there is an equal and opposite reaction

Definition and Characteristics of Force

• A force is a push or pull that causes an object to change its motion or shape, and is a vector quantity with magnitude and direction
• Force is measured in units of Newtons (N)

Types of Forces

• Contact Forces: arise from physical contact between two objects
  • Frictional force: resists motion between two surfaces in contact
  • Normal force: perpendicular force exerted by a surface on an object
  • Tension force: force exerted by a stretched string or wire
• Non-Contact Forces: act over a distance, without physical contact
  • Gravity: force of attraction between two objects with mass
  • Electromagnetic forces: forces between charged particles or magnets
  • Nuclear forces: forces that hold quarks together inside protons and neutrons

Resultant Force and Equilibrium

• Resultant Force: net force acting on an object, resulting from multiple forces acting simultaneously
• Equilibrium: state in which the net force on an object is zero, resulting in no acceleration

Newton's Laws of Motion

Law of Inertia

• An object at rest remains at rest, and an object in motion remains in motion, unless acted upon by an external force

Force and Acceleration

• F = ma: force applied to an object is equal to the mass of the object multiplied by its acceleration

Action and Reaction

• For every action, there is an equal and opposite reaction

Learn about the definition and types of forces, including contact forces such as frictional, normal, and tension forces. Understand the concept of force as a vector quantity with magnitude and direction.