The current theory of the structure of the Earth, called plate tectonics, tells us that the continents are in constant motion. Assume that the North American continent can be represented by a slab of rock 4350km on a side and 40km deep and that the rock has an average mass density of 2690kg/m^3. The continent is moving at the rate of about 4.8 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 units of J. c) A jogger (of mass 76kg) had the same kinetic energy as that of the continent. What would his speed be? Answer is units of m/s.
