Physics: Some scientists call it "the fundamental science," because of the way it underlies every other science. Think that atoms and molecules are only for chemistry class? Think again -- how those atoms move, and the nature of the subatomic particles that make them up, are province of physics. Think that black holes are only studied in astronomy? Not so -- there's a whole branch of physics that deals with the matter, energy and motion of the heavenly bodies. Among the sciences, probably mathematics rivals physics as a prerequisite to understanding every other field. (And yes, math is considered a science!)
For this quiz, we're not going to venture into the sexy (yet nearly incomprehensible) area of quantum physics. Don't worry, you won't need to know what they're doing at CERN, or what a Higgs boson really is. We're going to quiz you the stuff that bedeviled you -- or maybe the stuff you loved -- in middle school or high school. We're going to talk about the physics that keeps planes in the air, and makes baseball such a thrilling game to watch. And there'll be a few questions on the most famous physicists of all time. (A guy named Albert might come up).
Are you ready? No need for a No. 2 pencil -- just a love of this most beautiful of sciences!
Newton's First Law states that objects at rest shall remain at rest, unless what happens?
They are acted on by an external force.
Newton's First Law is summarized as the concept of inertia. In full, it says, "Objects in motion will stay in motion, and objects at rest will remain at rest, unless acted on by an external force." Common "external forces" are another moving object (a foot kicking a ball), air pressure (wind), or gravity.
Resistance is what is sounds like: a measure of the difficulty in passing an electrical current through a conductive, or not so conductive, substance. The opposite quality is conductivity, which is the ease with which current travels.
Newton's Second Law says that force equals mass times _____.
This is one of the simplest physics concepts to understand. People cock back their fist to punch because the mass of their fist doesn't change, so the way to pack a harder punch to to increase the speed at which it travels -- which requires starting from farther back.
True or false: Velocity and acceleration have the same meaning.
Acceleration is rate of change in speed. Does that make "speed" the same thing as "velocity"? In everyday life, yes, but not in physics. In physics, "velocity" describes speed in a known direction. If direction is unknown, the object just has "speed. "
A body's gravitational force is proportional to its ______.
This is one of the first things students in astronomy or physics learn: that the planets revolve around the Sun because of its great mass. Here's the kicker: Physicists know this is a universal law, but still don't know why mass creates gravity.
Volts are a measure of electric potential. Amperes are a unit of electrical current, and we didn't even get into joules or coulombs. Electricity is a complex subject, despite the fact that we use it daily. If you truly want to understand it, you'd be better off taking an electrical engineering course than a physics class.
You're probably used to hearing "concave" and "convex" when it comes to lenses, "planar" less often. A concave lens curved inward from the outer edges; a convex one outward. (Turn a spoon forward and backward to get an immediate visual on this).
The upward force that water exerts on objects is called ________.
Every physics student hears the story of Archimedes, who was able to determine if a crown was pure gold, or had lesser metals mixed in, by using buoyancy. Technically, Archimedes's revelation was more about displacement, but that's a concept closely related to buoyancy. Both gold and silver are too heavy to be held up by buoyancy, but the extent to which they displace water is different -- so Archimedes had a baseline for measuring how much water the crown should displace.
The height of a wave above its normal/center position is its _______.
When you're watching sound waves on a computer screen, (or, more likely, watched people watch sound waves on a screen in a movie with a lot of sciencey props) the amplitude is the top of the curve. Think of it like the vertex in a parabola.
The change in pitch of an ambulance siren, when the ambulance is in motion, is called the ______ effect.
A siren sounds higher in pitch if the emergency vehicle is approaching you, and get lower as it goes away. The same thing happens with light coming from moving sources, which moves up and down the color spectrum. This gives us the witty T-shirt with "The Doppler Effect" written in blue in front, and red in back.
If you own a salad spinner, you're familiar with centrifugal force -- the spinning causes water to fly to the outside perimeter. Centripetal force is the opposite, causing matter to move toward the center of rotation.
On Earth, gravitational acceleration is 9.8 _____ per second, per second.
Also written as "9.8 meters per second squared," this is the rate of acceleration at which objects to fall to earth, until they are stopped by hitting another object (like the earth) or reach an absolute velocity, which will vary depending on the property of the object.
A hypothetical process in which nuclear reactions could take place at room temperature is called _________.
There was a stir in the science world when two credible electrochemists claimed they'd achieved this. But the results couldn't be replicated, and the consensus of the scientific community is that it won't happen. Which is unfortunate, because the energy that cold fusion could provide the world would be incredible.
A change in the speed and direction of light is called ______.
You've seen visible evidence of refraction if you've seen a "rainbow maker," a crystal carved so that it creates a small rainbow when light hits it. This might be the only piece of physics equipment you can buy at your local New Age store.
_______ law reads, "The pressure of a gas, multiplied by its volume, is a constant."
This is an easier concept to understand than it at first appears. If you have air in a closed container, and squeeze the container so that the interior space gets smaller, the pressure of the air has to rise proportionally. This is why, under too much pressure, the lid of the container might blow off.
Which of these things is named after Isaac Newton?
a type of telescope
Newton is also the namesake of an early Apple computer and a mathematics institute at Cambridge. But we're partial to the Newtonian telescope, a long-bodied but inexpensive kind that uses a mirror, not a lens, to enlarge images.
Zero degrees on the ________ scale is called absolute zero.
You might have learned in school that this is the lowest temperature matter can reach, but that's not entirely true. At absolute zero, matter still retains zero-point quantum-mechanical energy. Which we'd explain, if we understood. Which we don't.
The amount of energy needed to heat one pound of water by one degree Fahrenheit is called a ________.
British thermal unit
The use of a Fahrenheit degree should have tipped you off, since the British, like the US, have stubbornly clung to the standard-measure system instead of centigrade. Perhaps that's why the BTU is rarely used compared to the joule.
The branch of physics studying the properties of light is called ______.
We tend to think of the prefix "opt-" as having to do with vision, thanks to "optometry" and "opticians." However, all vision is a function of light, and at its core, optics is the study of how light behaves, including its creation of color.
Which of these are you least likely to study in a physics class?
expansion of gases
the Krebs cycle
To an extent, every other science is dependent on the laws of physics. That's why it's sometimes called "the fundamental science." But the Krebs cycle, about how nitrogen goes from the earth's soil to the atmosphere and back again, is usually studied in biology classes.
Though it sounds very informal, "stiffness" is indeed a term from physics. It describes a material's ability to resist changing shape in response to an external force, which is important in engineering.
Physicists do refer to "visible light," but they're referring to the fact that we can see the objects that light illuminates, not light itself. They use the term "visible light," though, because in a larger sense, light is electromagnetic radiation, and there are spectrums of it that are completely invisible to humans -- they don't affect what we can see. Clear now?
Ferromagnetism is named for iron, of course. But other materials like nickel and cobalt are ferromagnetic. "Ferromagnetism" is simply the term for magnetism of metals, which is easily observed compared to other electromagnetic phenomena.
The Bernoulli principle is key to what modern convenience?
The Bernoulli principle has to do with how fast molecules of air travel over an airfoil -- a surface which is curved on top, in order to have greater area than it does on the bottom. The slower motion of air under the airfoil creates upward pressure. In this way, wings allow flight. It's really that simple!
A "newton" weighs about how much in standard measure?
a quarter pound (102 grams)
A newton is 102 grams, or about one-fourth of a pound. Why is this amount special enough to be named after Sir Isaac Newton? It represents the force that would cause a 1 kilogram object to accelerate 1 meter per second, squared.