Suppose a horizontal circular loop of wire has a diameter of 7cm and is lowered into sample of crude oil and suppose the additional force that is required to pull the loop out of the oil is 0.08N. Calculate the surface tension of the sample of crude oil. ​

During cooling, the kinetic energy of the molecules falls. why does this happen? a.the motion of the molecules increases. b. the motion of the molecules slows down. c.the van der waals forces between molecules decrease d. the forces of attraction between the molecules are overcome.