Leonard Bernstein
Chichester Psalms

Outline
Force
Pressure
Work
Energy
Potential Energy
Kinetic Energy
Transformations and Conservation of Energy
Heat

Force
 A push or pull
 Force = F
 Exerted by contact or at a distance
 Units = Newtons = N
 Weight = force of gravity

Newton’s Third Law
 For every force there is an equal but opposite reaction force.
Equal Magnitude
Opposite direction
Acts back on the “causing” object

Pressure
 Pressure = p
 Force = F
 Surface area = S
p = F/S  (N/m2)

Atmospheric Pressure
 Pressure = 1 x 105 N/m2
 = 1 atmosphere = 1 atm
 = 14.7 lbs./in2

Relative Pressure or Gauge Pressure
 Pressure above atmospheric pressure
 Absolute Pressure = Gauge pressure + 1 atm

Work
 Work = Force x Displacement
 Work = F x d = Fd
 Units = Nm2 = joule

Energy
 The ability of an object to do work as a result of its motion or relative position

Types of Energy
 Kinetic Energy
Energy of motion
 Potential Energy
Energy of relative position

Conservation of Energy
 Energy can never be created or destroyed.  It can only be changed from one form to another.

Damped Motion
 Friction - rubbing or contact
 Heat is a form of energy
 Heat removes energy from a system

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