Abumblebee buzzes past you at 3 m/s. the frequency of the hum made by its wings is 152 hz. assume the speed of sound to be 342 m/s. what is the observed frequency of the hum as the bumblebee approaches you?
you expect to have heat energy, electrical energy, and mechanical energy involved when you iron your clothes.
you don't expect chemical energy to show up, and if it does, it may ruin some of your clothes.
electron cloud and nuclei
explanation : when the lift falls, then the gravitational energy changed into the kinetic energy. gravitational potential is associated with the mass of the lift and its position. when lift starts from rest , the mechanical energy of the lift change in the form of potential energy.
when the lift down than the potential energy lost and kinetic energy is gained. lift loses height and gains speed.
the work is performed by the lift, when lift covers the distance against the gravitational force.