In an airless test-facility, a bullet is fired from a gun horizontally, at a height of 1 m. at the same time, another identical bullet is dropped from the same height. what is true about the acceleration of the two bullets while they are in flight?

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)