Physics

• Physics: branch of science dealing with interaction of matter and energy.
• Basic Quantities: length, mass, time, electric current, temperature, amount of substance, luminosity.
• Derived Quantities: quantities defined in terms of two or more of the basic quantities.
• Scalar: has magnitude and unit only.
• Vector: has magnitude, unit, and direction.
• Motion: change in position of a body.
• Displacement: distance with direction.
• Speed: The rate of change of position or displacement in a given time period.

  • Formula: speed = distance / time
  • Unit = (m/s)
• Velocity: the speed of something in a given direction

  • v = displacement / time
  • v = d / t; (m/s)
• Average Velocity: The average speed of an object over a period of time.

  • average v = (v1 + v2) / 2
• Acceleration: the rate of change in velocity with respect to time.

  • a = velocity / time
  • unit = (m/s^2)
• Projectile Motion

  • Motion of a body thrown horizontally and affected by Earth's gravitational pull.
• Trajectory

  • is the path taken by an object projectile motion.
• In Projectile Motion:

  • the velocity in the x-coordinate is constant, thus zero acceleration in the x-axis.
• In Projectile Motion:

  • the acceleration in the y-coordinate is constant, acceleration due to gravity = 9.8 m/s^2
• Net Force due to Gravity (Fg)

  • F = mass • acceleration (gravity)
• Body Thrown Horizontally (Fv) - Vertical Force

  • Fv = Fg = ma
• Resultant Velocity (Vr): the object moves in two directions at the same time, both horizontally (y-axis) and vertically (x-axis).

  • Vr = Vy + Vx
• Uniform Circular Motion (UCR) - A circular motion in which the velocity of the object is constant.
• Uniform Circular Motion [Fc = mac]

  • Centripetal Acceleration (ac) Formula

  ac = v^2 / R
• Uniform Circular Motion Formula; F = ?

  m x (v^2 / R)
• Force: push or pull. It is measure in unit Newton. It is an interaction between two bodies or between a body and its environment.
• Major Types of Forces - Contact Forces

  • Normal Force - it is a force exerted on an object by any surface with which it is in contact. This force is always perpendicular to the said surface.
• Major Types of Forces - Contact Forces

  • Friction Force - a force exerted on an object parallel to the surface, in the direction that opposes sliding.
• Different Types of Friction Forces

  • Static
  • Sliding/Kinetic
  • Rolling
• Formula for Friction Forces (Fr =)?

  Fn (µ)
• Tension: The pulling force exerted by a stretched rope or cord on an object to which it's attached.
• Electromagnetic Force: Attraction or repulsion between electric charges or magnetic poles.
• Coulomb's Law of Magnetism (Fe)

  • Fe = k (q1 q2 / r ^2)
  • k = 8.99 x 10 ^9 (N•m^2) / C ^-2
• Gravitational Force: attracts bodies toward each other.
• Law of Universal Gravitation (Fg)

  • Fg = G (m1m2 / r^2)
  • G = 6.67 x 10 ^-11 (N•m^2) / kg^2
• Weight: The gravitational force that the earth exerts on the body.

  • W = mg
• Newton's Laws of Motion

  • Law of Inertia: Bodies at rest will remain at rest and bodies in motion will continue to moving a t constant speed in a straight line unless acted upon by a net force". This law implies that objects will remain at rest or moving at a constant rate fi the sum of all forces acting on them is zero.
• Newton's Laws of Motion

  • Law of Acceleration: An unbalanced force acting on an object will cause the object to accelerate in the direction of the force.
  • Acceleration is directly proportional to the net Force and inversely proportional to it's mass.
• Newton's Laws of Motion

  • Law of Interaction: For every action there is an equal but opposite reaction.
• Elasticity: Property of matter that enables it to return to its original size and shape when the applied external force is removed.
• Stress: A component of a force perpendicular to the area it acts on. It is mathematically written as:

  • $Stress =$$Force/Area$
• Strain: A measure of deformation, usually it is the object's change in length, ∆l.
• Hooke's Law: Strain is directly proportional to the cause of deformation (stress).

   $Y =$$Stress / Strain =$$(F / A) ÷ (∆l / lo)$
• Young's Modulus of Elasticity (Y): is measure of the stretchability or compressibility of a material within its elastic limit. The higher Y is, the more elastic the material.