An explanation of what will happen every time in a specific situation

In which of the following cases is work being done on an object? question 2 options: pushing against a locked door carrying a box down a corridor pulling a trailer up a hill suspending a heavy weight with a strong chain

Which of these has some mechanical energy? a. an atom b. heat inside earth c. a book on a shelf d. the fire from a lit match

Consider the phase change taking place in the picture. you could use all but one statement to describe what is happening here. that is: a) temperature is increasing. b) kinetic energy is increasing. c) the space between the particles remains the same. d) the attractive force between the particles is decreasing.