Newtons Forces

Force

A push or pull on an object that can cause it to accelerate

System

The object or group of objects being analyzed for the forces acting on it

Free-body diagram

A diagram showing all the forces acting on a single object

Net force

The vector sum of all forces acting on an object

determines the object’s acceleration

Inertia

The tendency of an object to resist changes in its motion

directly related to mass

Translational equilibrium

Occurs when the net force on an object is zero

the object is either at rest or moving at constant velocity

Weight

The force of gravity acting on an object’s mass

calculated as W = m g

Gravitational field strength

The acceleration due to gravity at a location

on Earth it is approximately 9.8 N/kg

Apparent weight

The normal force acting on an object

the weight an object seems to have due to acceleration

Weightlessness

The condition in which no contact forces act to support an object

occurs in free fall

Drag force

The resistive force exerted by a fluid (like air or water) opposing the motion of an object through it

Terminal velocity

The constant velocity reached when the drag force equals the weight of a falling object

Tension

The pulling force transmitted through a string

Normal force

The perpendicular contact force exerted by a surface on an object resting on it

Inertia is directly related to the _ of an object.

mass

A non-zero net force causes _.

acceleration

An object in translational equilibrium has either no motion or ___ _____.

constant velocity

Two objects exerting forces on each other without contact are exerting a ___ force.

field

In considering motion

Newton’s 1st law of motion is about _ and came from ___.

Galileo

Increasing the net force on an object without changing its mass

_ the acceleration.

Increasing the mass of an object

while keeping the force the same

As a car collides head-on with a massive SUV

___ experiences an ___ and ___ force.

equal

opposite

A wagon is filled with sand. But

the boy in the wagon continues to toss sand overboard as it’s pulled. If the pull is constant

A falling raindrop reaches a terminal velocity before hitting the ground. At terminal velocity

the _ is equal to the of the raindrop.

weight

Four fundamental forces (strongest to weakest)

Strong nuclear

Electromagnetic

Weak nuclear

Gravity

Newton’s 1st Law of Motion

An object at rest stays at rest

Newton’s 2nd Law of Motion

The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. Formula: Fₙₑₜ = m a

Newton’s 3rd Law of Motion

For every action

forces always occur in pairs acting on different objects