At 11:00 a.m. on September 7, 2001, more than one million British schoolchildren jumped up and down for one minute to simulate an earthquake.
(a) Find the energy stored in the children's bodies that was converted into internal energy in the ground and their bodies and propagated into the ground by seismic waves during the experiment. Assume n1 = children of average mass m = kg jumped n = times each, raising their centers of mass by h = m each time and briefly resting between one jump and the next.
(b) Of the energy that propagated into the ground, most produced high-frequency "microtremor" vibrations that were rapidly damped and did not travel far. Assume e1 = % of the total energy was carried away by long range seismic waves. The magnitude of an earthquake on the Richter scale is given by

where E is the seismic wave energy in joules. According to this model, what was the magnitude of the demonstration quake?