Can someone please help me Its about fan carts

If jerome is swinging on a rope and transferring energy from gravitational potential energy to kinetic energy, is being done.

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

What do scientists use a scientific law for?