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 4000 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?
Answer in units of kg.

Part a constants huck finn walks at a speed of 0.60 m/s across his raft (that is, he walks perpendicular to the raft's motion what is huck's velocity (speed and direction) relative to the river bank? express your answer to three significant figures and include the appropriate units. relative to the shore)

Ametal ball with a mass of 0.028 kg is dropped from rest at a height of 1.0 meters above the ground. assuming the energy in the ball is conserved, how much kinetic energy will the ball have when it is 0.5 meters above the ground?

Will give brainliest! which statement best describes the difference between strong nuclear forces and weak nuclear forces? weak nuclear forces are involved when certain types of atoms break down. strong nuclear forces are responsible for holding atoms' nucleus together. weak nuclear forces hold bonds between atoms together. strong nuclear forces hold together the nucleus of an atom. strong nuclear bonds prevent atoms from falling apart. weak nuclear bonds prevent compounds from falling apart. strong nuclear forces are involved in breaking electrons from their shells. weak nuclear forces hold protons in the nucleus.