1. Physics Lab 2008-Energy

2. Linear Work  The act of exerting a force through a distance in the direction of the force (constant)  W = F  x cos   F = Force   x = Displacement  cos  = angle w.r.t. Force

3. Rotational Work  The act of exerting a torque through an angular displacement (fixed Axis)  W =    = Torque   = angular Displacement

4. Work Done by Pressure  The act of maintaining a pressure through a volume change (Constant Pressure)  W = P  V  W = Work,  P = Pressure   V = change of Volume

5. Work done by an Electric Field  The act of moving an electric charge within an electric field (Constant Field)  W = E q  x  E = Electric Field Strength,  q = electric charge,   x = Displacement

6. Linear Kinetic Energy  The ability to do work because of linear motion  KE = 0.5 m v 2  m= mass  V= linear velocity

7. Rotational Kinetic Energy  The ability to do work because of rotational motion. (fixed axis)  KE rot = 0.5 I  2  I = moment of Inertia   = angular velocity

8. Potential Energy  The ability to do work because of position within a force field

9. Gravitational Potential Energy  The ability to do work because of position within the gravitational force field  PE = mgh  m = mass  g = gravity (9.8 m/sec 2 )  h = height w.r.t reference

10. Spring Potential Energy  The ability to do work because of elongation or compression of a spring  U s =.5 k  s 2  k = spring constant   s = amount spring compressed or extended

11. Electric Capacitor Potential Energy  The ability to do work because of electric charges stored in an Electric Force field  U q =.5 q 2 /C  q = charge  C = capacitance

12. Pressure  Potential Energy per unit volume within a fluid (liquid and/or gas/vapor)  P = F/A  P = pressure  F = force  A = area

13. Ideal Gas Law  Relationship between energy stored in Ideal gas and its temperature  PV = nRT  P = pressure  V = volume  n = number of moles of gas  R = the energy to change the temperature of one mole of gas by one Kelvin  T=temperature in Kelvin

14. Power  The rate at which work is done or energy is transformed (used or generated)  P = W/  T  P = Power  W = Work   T = time to do work

15. Linear Power  The rate at which work is done during linear motion  P = Fv  P = Power  F = Force  v = velocity

16. Rotational Power  The rate at which work is done during rotational motion (Fixed Axis)  P =   P = Power   = Torque   = angular velocity

17. Electrical Power  The rate at which electrical energy is generated or transformed to other energy  P = VI  P = Power  V = Electrical Potential (Volts)  I = Current (Amps)

18. Ohmic Heating  The rate at which electrical energy is transformed into heat  P = I 2 R  P = Power  I = Current (Amps)  R = Resistance (Ohms)

19. Fluid Power  The rate at which a liquid fluid does work, (hydraulic)  P = pv  P = Power  p = pressure  v = volume flow rate

20. Efficiency  The ratio of usable energy resulting from an energy conversion to the total energy supplied for the conversion.

21. Efficiency of Work  e = W out /W in  W out = useful work out  W in = Total work input

22. Efficiency of Power  e = P out /P in  P out = useful power out  P in = Total power input

23. Efficiency of Energy Conversion  E= E out /E in  E out = Useful Energy out  E in = Total Energy Input

24. Other Notes  Any other equations the students must use must be provided by Event supervisor  All answers must be in SI Units ( Newton, Joule, Watt, Kilogram, meter, and second)  All answers must have the proper number of significant figures  Students may bring non-programmable calculator