On a side and 27 km deep and that the rock has an average mass density of 2790 kg/m3 . The continent is moving at the rate of about 3.8 cm/year. What is the mass of the continent

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 4850 km,on a side and 27 km deep and that the rock has an average mass density of 2790 kg/m3 . The continent is moving at the rate of about 3.8 cm/year. What is the mass of the continent

mass = 1.77 x 10²¹kg

Explanation:

the volume of the continent and then mass would be = Volume x density

Volume = (4.85 x 10⁶)²m x (27 x 10³)m

Mass = V x density

        =  (4.85 x 10⁶)² x (27 x 10³) x (2790)

        = 1.77 x 10²¹kg

i think it’s a. this is because if they measured the mass of something with a mass of 150g, then their final answer would have to be approximately 150g. though all of their answers are almost 150, rosa and tran have the closest answers (or the exact answer) to the accurate one.

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.