Objects 1 and 2 attract each other with a gravitational force
of 36.0 units. if the mass of object 1 is doubled and the
mass of object 2 is tripled and the distance separating
objects 1 and 2 is halved, then the new gravitational force
will be units.

The atoms in a nickel crystal vibrate as harmonic oscillators with an angular frequency of 2.3 × 1013 rad/s. the mass of a nickel atom is 9.75 × 10-26 kg. what is the difference in energy between adjacent vibrational energy levels of nickel? (h = 6.626 × 10-34 j • s, , 1 ev = 1.60 × 10-19 j)