Physics – Concepts – Force, Pressure and Energy Force, pressure and Energy are some of Physics basic tenets. The following will hopefully serve as a reminder of Physics 101.Force Pressure Energy Force: Force is described as what is required to change velocity oracceleration of an objects – recall that acceleration is any change in vector. The formula for force is rather simple: F = force required, given in Newton’s or Dyne’s m = the mass of the object, and a = acceleration The Newton (named after Sir Isaac Newton) is the amount required to move 1 kilogram at a distance of 1 meter in 1 second – written as: The equation of force is Newton’s second Law of physics. The three laws are: A body at rest must remain at rest and a body in motion remains in motion unless acted upon by an external force A force (F) on a body (m) gives it an acceleration (a) in the direction on the force, and is inversely proportional to the mass Whenever a body exerts a force from another body, that body exerts a force equal in magnitude and in the opposite direction of the initial mass. Here is Newton’s famous Force equation: Examples of force: Gravity and Friction Back to Top Pressure: Pressure is very similar to Force, but applies force over a particular area. The units of this equation will be: For comparison, 1 atmosphere (using Earth’s atmosphere at sea-level as a standard is: 14.7 lbs/in2 100 kPa 1 bar 760 mm Hg 29.92 inches Hg Back to Top Energy: Potential Energy (PE) – stored energy as a result of position: Kinetic Energy (KE) – energy of motion: Energy Units: 1 Joule (J) = Nm 1 erg = dyne cm = 10-7 J 1 calorie = 4.186 J 1 kilocalorie = 1 Calorie (food) Power: In order to determine power, we need to determine the value of Work: Angle = 0 degrees if force and work are in same direction Angle = 180 degree is force and work are opposite direction Angle = 90 degrees if force is perpendicular to work Now we can find Power: