Physics

• Law of Universal Gravitation


  Every point mass attracts every other point mass by a force acting along the line intersecting both points. The force is proportional to the product of the two masses and inversely proportional to the square of the distance between them.
• Law of Inertia

  An object in motion will remain in motion unless acted upon by an external force. An object at rest will remain at rest unless acted upon by an external force.
• Newton's First Law (Law of Inertia)


  F = 0 for an object at rest or moving uniformly (F is force, 0 is the net force)
• Newton's Second Law

  F = ma (Force is equal to mass times acceleration)
• Newton's Third Law

  For every action, there is an equal and opposite reaction. When two objects interact, they apply forces to one another that are equal in magnitude and opposite in direction.
• Law of Conservation of Energy


  Energy cannot be created or destroyed, only converted from one form to another.
• Law of Conservation of Momentum

  The total momentum of a closed system remains constant over time. The momentum of an object is equal to its mass multiplied by its velocity.
• Mechanical Energy

  Kinetic Energy: the energy of motion. Potential Energy: stored energy due to position or configuration.
• Thermal Energy

  Heat Energy: transferred between objects due to temperature differences.
• Electromagnetic Energy

  Electrical Energy: energy associated with electric charges and currents. Radiant Energy: energy transmitted through electromagnetic radiation.
• Chemical Energy

  Chemical Potential Energy: stored energy in chemical bonds.
• Nuclear Energy

  Nuclear Binding Energy: energy stored in the nucleus of an atom.
• Chemical Energy

  Chemical Potential Energy: stored energy in chemical bonds. Example: Food (glucose molecules) releasing energy through metabolism, converted into ATP (Adenosine Triphosphate) for various bodily functions.
• Nuclear Fission


  Nuclear Fission: process where an atomic nucleus splits into 2 or more smaller nuclei. Large amount of energy released in the form of heat, light, and radiation.
• Energy Release in Fission

  Neutrons, Gamma Radiation, Alpha Particles, Beta Particles, X-rays, and other forms of ionizing radiation.
• weight


  force a body exerts due to the pull of gravity
• mass


  the measure of the amount of material in a body
• weight=

  mass x velocity
• objects are stable if

  lower com

  large surface area
• objects will topple if

  vertical line through the com falls outside the base

  a moment is produced which causes the object to rotate
• com is


  the point where all the mass of that object may be considered to be
• balance at com because

  the moments on each side are equal
• density is

  mass per unit volume
• density=

  mass/volume
• density tells us

  how closely the particles are packed
• friction is

  a force that opposes motion
• air resistance or drag

  occurs when the object moves through air or fluid
• reduce friction by

  lubrication

  changing the material or fluid

  rollers

  streamlining
• friction acts in the

  opposite direction of the object
• friction exists

  when two surfaces move over each other
• a force can

  change the direction of motion

  change the shape of things

  start objects moving and slowing down
• 2 main groups

  contact and distant
• contact


  forces touch the object and produce a change of shape or state of motion
• distant


  forces act at a distance
• 1st law

  a body will remain at rest or move at a constant velocity if the resultant force acting on the body is zero
• balanced forces exist when

  two forces act in opposite directions but are the same size
• 2nd law


  if a resultant force acts on a body the body will not remain at rest or move at constant velocity, it will accelerate
• resultant force=

  mass x acceleration
• principal of moments


  when a object is balanced, the total sum of the clockwise moments is equal to the sum of the anticlockwise moments, about the pivot
• distance is

  ground covered