A) 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 5900 km on a side and 26 km deep and that the rock has an average mass density of 2800 kg/m^3. the continent is moving at the rate of about 4 cm/year. 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 kg.
c) a jogger (of mass 80 kg) has the same kinetic energy as that of the continent. what would his speed be? answer in units of m/s.

a.   mass number from atomic number

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.

+15-35=-20

going in opposite directions