Ch. 4 Mechanics I

Ch. 3 was about kinematics, explaining the motion of an object without the forces acting on it.

Ch. 4 is dynamics, we are looking at the forces causing the object to move.

Mass, Force, and Newton’s Laws

In the preceding chapter, we studied kinematics, which is the description of motion in terms of the object’s position, velocity, and acceleration. In this chapter, we’ll begin our study of dynamics, the explanation of motion in terms of the forces that act on the object.

A force is a push or pull exerted by one object on another. If you pull on a rope attached to a crate, you create a tension in the rope that pulls the crate. When a sky diver is falling through the air, the earth creates a downward pull called a gravitational force.

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