6. mr. walters is launching a toy rocket. the rocket experiences a force that pushes it up into the air. which of the following statements is true? the rocket fuel is shot downward with an equal force. the rocket has no mass, so it does not accelerate. the rocket exerts an upward force on its fuel. the air does not experience any force as the rocket passes through it.

the earth’s crust is broken into separate pieces called tectonic plates (fig. 7.14). recall that the crust is the solid, rocky, outer shell of the planet. it is composed of two distinctly different types of material: the less-dense continental crust and the more-dense oceanic crust. both types of crust rest atop solid, upper mantle material. the upper mantle, in turn, floats on a denser layer of lower mantle that is much like thick molten tar.

each tectonic plate is free-floating and can move independently. earthquakes and volcanoes are the direct result of the movement of tectonic plates at fault lines. the term fault is used to describe the boundary between tectonic plates. most of the earthquakes and volcanoes around the pacific ocean basin—a pattern known as the “ring of fire”—are due to the movement of tectonic plates in this region. other observable results of short-term plate movement include the gradual widening of the great rift lakes in eastern africa and the rising of the himalayan mountain range. the motion of plates can be described in four general patterns:

collision: when two continental plates are shoved together

subduction: when one plate plunges beneath another (fig. 7.15)

spreading: when two plates are pushed apart (fig. 7.15)

transform faulting: when two plates slide past each other (fig. 7.15)

muslims have taken his goods and products to different parts of asia an indonesia. sometimes just traveled and trade, but in other occasions, stayed in the place and made a living.

trade was the key for muslims economies to prosper. their commerce routes reached far places like malaysia and java in the 11th century.

another important factor for prosperity was that muslim states served as the middle point for european traders.

they used to travel by land but sailing the seas -the indian ocean- really increase the exportation of products.