Which of the following is a theory stating that one plate is forced beneath another plate? (Choose one) :

1.) theory of Permian Extinction

2.) theory of plate tectonics

3.) theory of subduction

4.) theory of Pangaea

Velocity is a description of both speed and direction, therefore it - a vector - a force arrow - the same as acceleration - a magnitude

What effects result when there is an impact between earth and an asteroid? check all that apply. a.massive flooding. b.extinction of many life forms.c.major earthquakes change in average global temperature.d. giant dust cloud

Asolid cylinder and a cylindrical shell have the same mass, same radius, and turn on frictionless, horizontal axles. the cylindrical shell has light-weight spokes connecting the shell to the axle. a rope is wrapped around each cylinder and tied to blocks of equal masses that are held the same height above the ground. both blocks are released simultaneously. the ropes do not slip. which block hits the ground first? or is it a tie?