23-1-the-four-fundamental-forces_summary

This section discusses the Four Fundamental Forces: gravity, electromagnetism, weak nuclear force, and strong nuclear force. These forces are responsible for all interactions known to science, from the very small to the very large. Students will learn about the carrier particles that transmit these forces, how particle accelerators work to gather evidence about particle physics, and the relative strengths and ranges of the four forces. Gravity is the weakest of the four fundamental forces and explains common observations such as a dropped ball falling to the ground and the motion of planets. The electromagnetic force is responsible for electrostatic interactions and the magnetic force seen between bar magnets. It is behind common physics forces like friction and the normal force. The strong nuclear force is an attractive force that exists between all nucleons and is the strongest force at short ranges. The weak nuclear force is responsible for beta decay and has a shorter range than the strong force. The forces are transmitted by carrier particles, such as the photon for the electromagnetic force and the pion for the strong nuclear force. The strong force is transmitted by the exchange of particles called gluons. The weak nuclear force is transmitted by particles called W and Z bosons. Particle accelerators, such as the Van de Graaff generator, cyclotron, synchrotron, and Large Hadron Collider, are used to create matter from energy and to accelerate known particles to high velocities. This allows scientists to study the properties of particles and to discover new particles. Teacher Support: The section learning objectives will help students master the following standards: (5) Science concepts. The student knows the nature of forces in the physical world. The student is expected to: (H) describe evidence for and effects of the strong and weak nuclear forces in nature.