The mechanical advantage required to lift a clay block?

Can someone me with questions 12 and 13 plz.

Design techniques and materials that reduce the negative environmental impact of a structure are referred to as

The bond energy for the van der waals bond between two helium atoms is 7.9×10−4ev. assuming that the average kinetic energy of a helium atom is (3/2)kbt, at what temperature is the average kinetic energy equal to the bond energy between two helium atoms