The force of friction between an object and the surface upon which it is sliding is 15N. The mass of the object is 20kg. What is the coefficient of kinetic friction?
1

explanation:

as the height from which the ruler was dropped increased, the speed of the ruler at ryan's hand increased.

the entire statement is true and correct.  

there's no diagram, nothing is illustrated, and no question is asked.

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.