# Classical Mechanics: The HowStuffWorks Quiz

Tasha Moore

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Do the sciences, especially physics, intimidate you? Break that annoying habit now and dive into matter and motion concepts that are really easy to grasp. You'll be a wise one after acing this classical mechanics drill. We promise to guide you along your intellectual journey from query to query by providing comprehensive explanations and clever hints to help you score better than you thought you ever could on a science exam!

But first, get a sound understanding of how classical mechanics came to be. English physicist and mathematician Sir Isaac Newton set things in motion with his seminal 17th-century work "Principia." Before Newton came along, folks understood the motion phenomenon in more of a philosophical context. Newton streamlined old ideas with his new principles and the rest is history. Newer subdivisions of classical mechanics and more refined ways of understanding the discipline keep surfacing. If you didn't know it by now, we are living in exciting science times. Our quiz helps you to gain a greater appreciation for the scientific innovations that make the headlines each day.

This quiz begins with the premise that sums up most of what classical mechanics is all about: "An object at rest stays at rest." From there, you'll roll through enlightening motion concepts that are sure to satisfy your science cravings. So dig in!

# Classical mechanics is a branch of which scientific discipline?

Classical mechanics deals with how an object behaves when it is subjected to forces of various sorts. It also is concerned with the types of forces that act on objects that are not in motion.

# The scientist who first articulated the general principles of classical mechanics was ________?

English scientist Sir Isaac Newton established the main principles of classical mechanics in his 1687 work titled "Philosophiae Naturalis Principia Mathematica," or "Principia" for short. Relativity and quantum mechanics, which are based on Newton's principles, were developed in the 20th century.

# According to the planetary motion concept, a comet moves in what manner of orbital motion with the sun?

Johanes Kepler's second and third Laws of Planetary Motion are in sync with Newton's Law of Universal Gravitation. The theoretical basis of the elliptical motion of planets and comets is based on Newton's attractive gravitational force law.

# Equilibrium theory is intricately linked to which concept?

The rotational effect of a force relies on the direction of the force and the force's magnitude. Torque is specific to an axis of rotation, as with a seesaw apparatus, for example. The force vector lies in a plane parallel to the axis.

# Forces that can be expressed as the subtraction of the increase or decrease in magnitude of a potential are ________ forces?

Not all natural forces are conservative forces. A force that acts on charged particles in a magnetic field, for example, relies on particle velocity as well as particle position. Gravity is a conservative force.

# We call the instantaneous acceleration of a particle moving in a circle formation with consistent speed, what?

Circular motion is non-rectilinear motion, or motion that is not in a straight line. Change of particle direction, as defined by an acceleration component, while moving along a circular formation largely distinguishes circular motion from non-rectilinear motion.

# The discipline chiefly concerned with forces that affect at-rest bodies or bodies in equilibrium is ________?

In contrast, dynamics is the study of bodies in motion. Civil engineering utilizes statics, which is a subdivision of classical mechanics, to determine theoretical forces that might affect dams, bridges, buildings, and the interconnected components of these structures, in particular.

# In the equation F = ma, "a" means, what?

That a particle's path is a crucial position of action is the basic concept behind Lagrangian classical mechanics, which is derived from Newton's law F = ma, where "F" equals force and "m" equals mass. Joseph-Louis Lagrange's 1788 text Mécanique Analytique provides more subdued mechanics analysis.

# A body's measure of inertia can also be expressed as its ________?

In physics, the mass and weight of an object are distinct. The mass is an object's tendency to not sway from consistent motion in a straight line when affected by external forces. An object's weight is the magnitude of force and is dependent on the object's location.

# An object won't change the manner in which it moves unless a ________ acts upon it?

Considering Newton's F = ma principle, where "m" is mass and "a" is acceleration, it is more difficult to affect an object of greater mass than an object of smaller mass when both objects are acted upon by forces ("F") of the same magnitude. The bigger the mass, the less the acceleration.

# In physics, gravity is also an object's ________?

An object's weight is not intrinsic to the object since the object's weight is based on its location. Gravity's pull on a body varies according to the object's location on Earth. However, gravitational pull is greater for objects of greater mass.

# Are you confident that you can choose the equation that correctly expresses Newton's second law of motion?

Newton's second law of motion takes into consideration the net forces, or total force, acting upon an object. Normal force is determined by the direction of the acceleration such that a sum of all contributing forces perpendicular to the direction equals zero.

# Can you name the ancient Greek philosopher who theorized that Earth was the center of the universe?

Sir Isaac Newton's classical mechanics theorized motion as a natural phenomenon that can be explained mathematically. Newton insisted, and modern physics agrees, that an object does not move or behave simply as a result of the object's proximity to humans, which is an Aristotelian concept.

# Do you know the branch of classical mechanics that analyzes atomic phenomena?

Quantum mechanics improves upon classical mechanics theories regarding areas of physics that Newton had little knowledge of. Quantum mechanics explores atomic- and subatomic-level factors that require the application of advanced physics concepts, such as Planck's constant.

# For every action, there is an equal and ________ reaction?

This is Sir Isaac Newton's third law of motion. Newton expounded further, saying, "The mutual actions of two bodies upon each other are always equal , and directed to contrary points." Press your hand against a wall, and the wall presses your hand at the same time.

# Do you understand the area of classical mechanics that deals with phenomena that occur at extremely high velocities?

In addition to quantum mechanics, special relativity theory is a basis for modern physics hypotheses concerning uniform motion and inertial frames. German-born physicist Albert Einstein developed the ground-breaking theory of relativity in 1905.

# In what language did Sir Issac Newton write his "Principia" analytical work published in 1687?

Newton's "Principia" was first published in Latin, but he proved his core mathematical concepts that define classical mechanics geometrically. The English translation of the "Principia's" full title is "The Mathematical Principle of Natural Philosophy."

# How would you complete Newton's own words regarding his first law of motion: "Every body ________ in its state of resting, or uniformly moving in a right line, unless it is compelled to change that state by forces impressed upon it"?

In other words, as it is more popularly repeated: "An object in motion stays in motion." An object's velocity is consistent only when there are no forces acting upon the object, or if the sum of all forces acting on the object equals zero.

# Do you recognize the principle technique that Sir Issac Newton developed in order to explain classical mechanics concepts in his "Principia" work?

Scientific method is the procedure still utilized today. Newton revolutionized scientific understanding by merging mathematical analysis with experimental induction through observation.

# Try to quickly choose the term used in classical mechanics to describe expeditious phenomena.

Instantaneous positioning describes a particle's position at a specific point in time. Instantaneous velocity, instantaneous acceleration, instantaneous power, instantaneous length and instantaneous axis are all terms that express respective physics attributes in relation to a specific moment in time.

# This German physicist discovered a method for contriving quantum mechanics using matrices. Do you know who he is?

Werner Heisenberg was awarded the 1932 Nobel Prize for Physics for his quantum mechanics discovery, which he conceptualized in 1925 and formally communicated in 1927. Heisenberg's concepts are based on his uncertainty principle, also called the indeterminacy principle.

# Try to select the term used in classical mechanics that describes the rate of change of velocity.

Acceleration is intricately tied to time; average acceleration is the velocity rate of change over a time interval. Instantaneous acceleration means average acceleration over a minuscule time interval. Acceleration is a derived quantity that can be conveyed as a combination of length, time and mass.

# Can you spot the discipline that is not a subdivision of classical mechanics?

During the twentieth century, Newton's classical mechanics theories were challenged and modernized by scientists such as William Hamilton and Joseph-Louis Lagrange. In the twenty-first century, mechanics concepts have been refined further through catastrophe and chaos theories.

# Is it a challenge for you to identify the term commonly used to describe how motion is expressed mathematically?

Kinematics, per say, does not quantify anything in physics. It can be perceived as a universal mathematical language of classical mechanics that clearly exemplifies the motion laws of physics.

# Try to select the option that is not a fundamental concept of classical mechanics.

Frictional force develops when an object slides over a rough surface, thus hindering the object's movement. Computationally, friction is expressed as a normal reaction constant of proportionality dependent on the nature of the surface, which is multiplied by a coefficient of dynamical friction.

# How easy is it for you to select a unit of measurement for momentum?

What Newton defined as "motion" is referred to as "momentum" today. The momentum of a particle is mass times a velocity vector. A system's "momenta" is often analyzed in physics, as with angular momentum loss in astrophysics by which gravity's influence on massive interstellar bodies is examined.

# Classical mechanics is the study of the relationship between ________ and ________.

One of the first things that a physicist does when considering the relationship between forces and motion is determine which forces affect a particular body. Bodies exert forces on other things, causing a pull and push scenario which must be considered when assessing an object's net force.

# Can you guess the name of the scientist who contributed to classical mechanics by devising a solution for the "three-body problem"?

French mathematician Alexis Clairaut deduced a satisfactory result for the three-body problem. These kinds of problems take into consideration three points of mass that interact gravitationally. Classical mechanics typically evaluates two moving points of mass in an isolated dynamic system.

# Mathematically, gravitational force is the same as ________ force.

Static charge distributions generate electric fields, which are termed electrostatic. Electrostatic force is an electrical force applied between two stationary charges. This concept is named after French scientist Charles-Augustin de Coulomb who devised the electrostatic law of force in 1788.

# When a planet is closer to the Sun, it moves faster. What is this phenomenon called?

Planets move elliptically around the Sun. The perihelion of a planet body is the position on a planet's orbit that's closest to the Sun. When processing planetary perihelion, interplanetary forces are defined as uniform concentric rings centered at the Sun with radius being the mean orbital radius.

# What is another way to express Sir Issac Newton's first law of motion?

Italian physicist Galileo Galilei was the first to conceptualize the concept of inertia, that an object maintains constant velocity unless affected by an external force. This quality is essential to all bodies of matter. Newton later streamlined the concept into the classical mechanics laws.

# Classical mechanics assesses an object's speed and ________.

Two simple cases in classical mechanics are when a body is at rest and when a body maintains constant velocity, or a constant rate of speed in the same direction over a level planar surface. When assessing velocity changes, the change in time must be kept small as not to void the velocity vector.

# What aspect of speed does acceleration quantify?

Average velocity quantifies an object's change of position over time, while acceleration determines its change (increase) in the rate of speed. Therefore, acceleration assesses velocity's rate of change over time.

# Can you figure out the type of motion whereby an object shifts from one position in space to another?

In classical mechanics, translational motion and rotational motion are analogous in that the two types are expressed similarly mathematically. A rolling (rotating) bowling ball moving (translating) down a bowling lane is an example of both translational motion and rotational motion at play.

# Try to pick the choice that is a real-world example of both translational motion and oscillatory motion.

In physics, a moving body that oscillates regularly changes position or magnitude around a center point. Generally, the magnitude of the natural restorative force on an object (to return the object to a state of equilibrium) is proportional to the object's equilibrium displacement.

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