What information about an object can be used to describe its motion?
A.
direction, position, and mass
B.
mass, position, and speed
C.
position, direction, and speed
D.
speed, mass, and direction

You don't need the object's mass to describe its motion. The direction and speed can be combined to form the velocity vector. The position along with the velocity vector helps us determine where the object is likely to end up next.

An example is this: We have a truck in city A and it's traveling north to city B at a speed of 50 mph. It's position is in this city. It's velocity is composed of the speed of 50 mph and the direction is north. All of these three factors help us conclude that the truck is likely aimed for city B.

the rocks are classified by the geological process they are formed by. the three main groups of rocks are igneous, metamorphic, and sedimentary. minerals are not they are classified under the chemical classes they are in. these groups include silicates, sulfates and carbonates.