Chapter 5-  Work and Energy

1.  Work done by a constant force-    W =( F cos q ) x

                                                                Units 1 Joule(J) = N.m

      Kinetic energy (KE)  =  ½ mv²

     Work-energy theorem       W =  ½ mv²_f  - ½mv²_o

      Gravitational potential energy (GPE)  =  mgy

      Energy stored in a spring = ½ kx²

2.    Conservative and non-conservative forces

       Conservation of mechanical energy-    W_nc  =  E_f - E_o

       When W_nc = 0 , then E_f = E_o

3.     Power (P)   =  W/t

       units  1 watt(w) =  1joule/s

        P_ave = Fv

Chapter 5-  Uniform Circular Motion

1  Motion of a body traveling at constant speed in a circular path- is what is meant by uniform circular motion

    Such a body' velocity vector is continuously changing resulting in an acceleration directed towards the center of the circle(centripetal acceleration) 

    Centripetal acceleration. -  v²/r

    Centripetal force    F_c  = mv²/r

2.  Centripetal force and safe driving

     Satellites in circular orbits

     Apparent weightlessness

     Artificial gravity