Discuss the observations of the effects of energy. Recall that impulse is force times time but work does not include a time element, but does include a distance element. Introduce work as net force over a distance. Force is in Newtons, distance in meters and therefore work is in Newton.meters or Joules. Determine why lifting an object over your head requires work, but holding the lifted object above your head does not. Discuss some forces that work is done against: elasticity, gravity, weight and friction. Introduce the concept of power as how fast work is done. Outline the formula for power determination and the unit as the watt.