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Book Chapter |
The motion of simple pendulums has played an interesting role in physics and technology. The simplest pendulum to study would probably be a compact mass attached to a long string. Physicists call this “the simple…
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For those of us who grew up with conventional electromagnets, it is very strange to see an electromagnet that is not connected to an external power source. But that is what happens with a superconducting magnet. After a…
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It seems almost counterintuitive that wet air should be less dense than dry air and float in the sky. But the beauty of the cirrus and cumulus attest to this as we gaze at the myriad shapes and forms above us. Cloud…
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Medical questions were very important during the Skylab mission from May 1973 until February 1974. At the most basic level the scientists wanted to know if the astronauts would lose weight during prolonged stays in…
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In what now seems like physics folklore, the young patent clerk Albert Einstein proposed that light behaves like a particle—known as a photon—and that each photon has an energy that depends on its frequency. More…
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Although Isaac Newton probably never bowled a perfect 300 game, his physics can be used to analyze the sport of bowling. The collision of the ball with the bowling pins—and the collisions of the pins themselves—must…
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A converging lens bends all rays of light parallel to the principal axis (the axis of symmetry of the lens) in such a way that they converge at a single point referred to as the focus. The lens also takes the light…
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Edwin Hubble showed that most stars (and galaxies) are receding from Earth. Because of the expansion, the frequencies of the spectral lines from the stars are shifted to lower values—that is, the light is redshifted.…
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When we think of forces, we usually imagine a push or a pull. Such a push or pull is assumed to be in the direction of the line connecting the pusher and the object pushed. Not so with the Lorentz force. A magnetic…
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Nature has exhibited the effects of a variable index of refraction for a very long time. The index of refraction of air varies with its density. Therefore, the index of refraction of the Earth’s atmosphere decreases…
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Hos fast can you throw a baseball? How fast is a speeding bullet? Restricted to simple tools in the laboratory, this chapter explains how both measurements can be completed with a clever approach and some elementary…
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Every school-age kid has heard the prediction “What goes up must come down.” Many kids challenge it with a question relating to helium balloons. Some inquisitive and persistent kids have wondered what would happen if…
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Watching the Olympic Games is a reminder of the versatility of physics. The equations for projectile motion can be used to analyze many different track and field events. The athletes are not required to understand all…
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All of the scenarios presented in this chapter have similar solutions. The trajectory of any object can be analyzed (without air resistance) by recognizing that the horizontal and vertical motions are independent of one…
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Light plays such a crucial role in our lives that it’s very hard to imagine a universe without light. But what is light? How do we describe its behavior? We have two basic models that we can use to describe light—…
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