The diameters of the main rotor and tail rotor of a single-engine helicopter are 7.65 m and 1.05 m, respectively. the respective rotational speeds are 454 rev/min and 4,130 rev/min. calculate the speeds of the tips of both rotors. compare these speeds with the speed of sound, 343 m/s.

Astone weighing 1.5 kilograms is resting on a rock at a height of 20 meters above the ground. the stone rolls down 10 meters and comes to rest on a patch of moss. the gravitational potential energy of the stone on the moss is joules.

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)

Based on details in the riddle of the rosetta stone, which statement best describes jean-baptiste fourier’s influence on jean-françois champollion?