The current theory of the structure of the Earth, called platetectonics, tells us that the continents are in constant motion.Assume that the North American continent can be represented by aslab of rock 4200 km on a side and 25 km deep and that the rock hasan average mass density of 2910 kg/m3 . The continent is moving atthe rate of about 1.8 cm/year.
a-What is the mass of the continent? Answer in units of kg.
b- What is the kinetic energy of the continent? Answer in unitsof J.
c- A jogger (of mass 70 kg) has the same kinetic energy as thatof the continent. What would his speed be? Answer in units ofm/s.
