If an object is thrown up at an initial velocity of 9.8 m/s, how long will it take to fall back to the ground?

In the first law of thermodynamics, triangle e=q-w, what does q stand for

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

Aforce is a vector quantity because it has both?