Chapter 4: Newton's Laws and Applications

Mass

an object’s property that determines how hard it is to change its velocity

A ______ mass will be hard to accelerate

Large

Force

The thing that is representative for an objects change in velocity

A force is a _____ or a _____

Push, pull

According to Newton’s second law, the direction of the object’s net force will also be in the direction of what?

The object’s acceleration

Newton’s First Law

All objects at rest stay at rest unless acted upon by an external force; all objects in uniform motion stay in uniform motion unless acted upon by an external force.

If external force = 0, then…

a = 0 and v = constant

Newton’s Second Law

The acceleration of an object is directly proportional to the net force acting on it, and inversely proportional to its mass

When are Newton’s 2nd and 3rd Laws negligible? What’s an example?

In a non-inertial reference frame; a person in a car going around a corner

Newton’s Third Law

Every force has an equal and opposing force; these opposite forces act on different objects

Normal force

A force perpendicular to the contact surface of two objects; always opposes the surface?

Friction force

Parallel force to the contact surface between two objects that opposes the direction of motion

Tension force

A pulling force in the direction parallel to the rope or chain

In the absence of external forces, tension force is equal to what? How is this expressed?

mg; T = mg

For a light, massless rope, the magnitude of tension is the ______ at ______ ends

same, both

An object with a net force = 0 is in what?

Equilibrium

This equilibrium applies to objects at rest

Static equilibrium

This equilibrium applies to an object moving along a straight line with a constant velocity

Dynamic equilibrium