Chapter 3: Forces and Newtons Laws of Motion

Isaac Newton

________ published his work, the Mathematical Principles of Natural Philosophy, in 1687, revolutionizing the rational study of mechanics by introducing mathematical principles that all of nature was considered to obey.

circular path

If the centripetal force acting on an object is not sufficient to keep it moving in a(n) ________, the object will move outwards, away from the center of the circle.

outward ones

Radially inward forces are positive and ________ are negative.

Weight

________ is a vector force that depends on an object's location in the universe, while mass is a scalar measure of an object's inertia.

gravitational field strength

The ________ (g) is the same as the acceleration due to gravity in free fall and projectile motion.

Free body diagrams

________ are a visual tool used to represent the forces acting on an object.

minimum coefficient of friction

A car (mass M) takes a turn (of radius R) on a flat road without any slipping or sliding at a constant speed S. Find an expression for the ________ needed between the wheels and road.

Centripetal force

________ is the force that keeps an object moving in a circular path.

state of motion

The ability of an object to resist a change in its ________ is called inertia.

unbalanced force

Forces that produce a nonzero net force, which changes an object's motion

balanced force

Forces on an object that combine to give a zero net force and do not change the motion of the object.

friction

A force that opposes motion between two surfaces that are in contact

sliding friction

Friction that occurs when one solid surface slides over another

rolling friction

Friction that occurs when an object rolls over a surface

terminal velocity

The constant velocity of a falling object when the force of air resistance is equal in magnitude and opposite in direction to the force of gravity

inertia

An objects resistance to change its motion

free fall

The motion of a falling object when the only force acting on it is gravity

air resistance

the fluid friction experienced by objects falling through the air

net force

The combination of all forces acting on an object

Newton's second law

Acceleration is produced when a force acts on a mass. The greater the mass (of the object being accelerated) the greater the amount of force needed (to accelerate the object).

Newton's third law

For every action by a force, there is an equal and opposite reaction by another force.

newton's first law

An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force.