A 1.5 kg rock is dropped from a height of 2.0 meters onto a spring that compresses and brings the rock to rest. (Assume no losses to thermal
energy.) How much energy is in the system before the drop.

Two models of the same compound are shown. in what way is model b better than model a? model b shows the types of elements in the compound, but model a does not. model b shows the three-dimensional shape of the molecule, but model a does not. model b shows how the atoms in the molecule are connected, but model a does not. model b shows the number of atoms of each element in the molecule, but model a does not