Answer: 2.7 x 10 -6 rad/s.
- A 2.7 x 10<sup>-6</sup> rad/s
- B 2.5 x 10<sup>-6</sup> rad/s
- C 7.3 x 10<sup>-5</sup> rad/s
- D 1.2 x 10<sup>-5</sup> rad/s
Correct answer: A. 2.7 x 10<sup>-6</sup> rad/s
Explanation: omega = 2*pi/T = 2*pi/(27 x 24 x 3600) = 6.28/2332800 approx 2.7 x 10<sup>-6</sup> rad/s.
g is maximum at Earth's surface; going up, it falls off as 1/r² (inverse-square); going down, it falls off linearly with depth (since only the mass enclosed within radius r contributes), reaching zero at the centre.
Concept context
Universal gravitation, orbital mechanics, gravitational potential, and escape velocity.