Science

• The following are the best examples of a projectile motion

  • A ball launched horizontally
  • A ball kicked from the ground at an angle
  • A stone thrown into the air
• In a projectile

  • The horizontal component of the velocity is constant while the vertical component is accelerating
• When the velocity is constant, the acceleration equals zero
• At the highest point, the velocity of a projectile is equal to the horizontal velocity
• Projectile

  When an object is acted upon by gravity alone
• Momentum


  The product of mass and velocity
• When the velocity of an object is doubled


  The momentum is also doubled
• 
  

  Impulse is a Changes the momentum of a body
• The two forms of Mechanical energy


  • Kinetic Energy - energy in motion
  • Potential energy - energy at rest by virtue of its position
• The law of conservation of energy states that energy is neither created nor be destroyed
• Examples of interchanged between kinetic and potential energy


  • A swinging pendulum
  • A bouncing ball
  • A vibrating spring
  • Rest to falling
• Internal energy


  The sum of all kinetic and potential energy of molecules in a system
• Thermodynamics


  The study of heat and its transformation to other forms
• The law Conservation of energy is also known as the 1st Law of thermodynamics
• The mechanical work needed to produce a given amount of heat was first experimented by Benjamin Thompson
• Adiabatic process


  A process in which no heat transfer takes place
• Isothermal process


  A thermodynamic process in which the temperature of a system remains constant
• Units of the given quantities


  • Heat - calorie (cal)
  • Energy - Joules (J)
  • Force - Newton (N)
  • Velocity - meters per second (m/s)
  • Distance - meter (m)
  • Momentum - kilogram meters per second (kg-m/s)
  • Impulse - Newton meter (N-m)
  • Acceleration - meters per second squared (m/s²)
  • Time - seconds (s)
  • Mass - kilogram (kg)
• Sample problem 1


  What is the momentum of a 2000 kg car if it's moving at a velocity of 2.5 m/s?
• Sample problem 2

  Find the work done of a little boy in pulling a 2-kg box to a distance of 30 meters?