Acoin dropped from the top of a precipice takes 5.00 s to hit the ground. how high is the precipice

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

Anthracite is so hard and pure it is also referred to as a renewable resource metamorphic rock hot bituminous coal dirty fuel

The reactions of photosynthesis occur in the of plant cell? a. mitochondria. b. lysosomes. c. chloroplasts. d. chlorophyll