Newton's Laws of Motion

Flashcards based on lecture notes regarding Newton's First, Second, and Third Laws of Motion, including inertia, mass/force relationships, and specific numerical examples.

Newton's First Law of Motion

A law stating that an object at rest remains at rest and an object in motion remains in motion (in a straight line at a constant speed - no acceleration) unless acted upon by a net force.

Law of Inertia

Another name often given to Newton's First Law of Motion.

Inertia

The property of an object that resists changes to its motion; it makes stationary objects difficult to move and moving objects difficult to stop.

Mass

The physical quantity that determines the amount of inertia an object possesses.

Newton's Second Law of Motion

A law stating that when a net force acts on an object, it accelerates in the direction of the net force.

$$\Sigma \vec{F} = m\vec{a}$$

The mathematical equation for Newton's Second Law, where units are Newtons ($N$) for force, kilograms ($kg$) for mass, and $m/s^2$ for acceleration.

Direct Relationship in Newton's Second Law

The principle that acceleration varies directly to the net force acting on an object.

Inverse Relationship in Newton's Second Law

The principle that acceleration varies inversely to the mass of the object.

Newton's Third Law of Motion

A law stating that for every action force there exists a reaction force that is equal in magnitude but opposite in direction.

Calculated acceleration (Example 3)

The result when a net force of $4500\,N$ acts on a $1600\,kg$ racecar, yielding an acceleration of $2.8\,m/s^2$.

Mass calculation (Example 4)

Given a force of $3.3\,N$, an initial rest state, and a final speed of $5.5\,m/s$ over $12.0\,m$, the calculated mass is $2.62\,kg$.

Net Force and Acceleration (Example 5)

When a stationary $5.00\,kg$ block has a friction force of $7.00\,N$ and an applied force of $6.20\,N$, the net force is $-0.80\,N$ and the acceleration is $-0.16\,m/s^2$.

Distance calculation (Example 6)

The distance an object moves from rest over $5.00\,s$ with an adjusted acceleration of $2.25\,m/s^2$ is $28.1\,m$.

Final Speed (Example 7)

The speed of a $25.0\,kg$ object after being pushed by a $17.0\,N$ force against $10.0\,N$ of friction for $5.0\,s$ is $1.4\,m/s$.