FORCES (1)

Natural Disasters Hurricane Katrina (2005) Typhoon Yolanda (2013) Understanding Forces

Types of Forces

• Contact Forces: These are forces that occur from physical contact between two objects. They include:

  • Frictional Force: The force resisting the motion of solid surfaces, fluid layers, and material elements sliding against each other.

  • Applied Force: A force that is applied to an object by a person or another object.

  • Normal Force: The support force exerted upon an object that is in contact with another stable object.

• Non-Contact Forces: These are forces that act at a distance without physical contact. They include:

  • Gravitational Force: The attraction between two masses; it is a force that pulls objects toward one another.

  • Electromagnetic Force: The force responsible for electricity and magnetism; it affects charged particles and can either attract or repel them.

  • Nuclear Force: The force that holds protons and neutrons together in an atomic nucleus, overcoming the electromagnetic repulsion between protons.

Vector and Scalar Quantities

• Scalar: A quantity that has only magnitude (size) and no direction. Examples include mass and temperature.

• Vector: A quantity that has both magnitude and direction. Examples include force, velocity, and displacement.

Sir Isaac Newton and Gravity Observation of an apple falling led to the theory of gravity as a universal attraction force.