A spherical boulder with a volume of 1800 m3 and a density of 2.7 x 10 3 kg / m3 starts to roll down a 30 degree incline that is 130 m long. At the end of the incline is a 450 m cliff. How far in the horizontal will the boulder have traveled upon landing? (Hint: First estimate the speed that the boulder will roll off the cliff. Total center of mass plus rotational kinetic energy of a rolling spherical object is 7/10 mv2.)