What is Physics?
As I researched, I found many different definitions of Physics, some being very complex and others being simple and to the point. In defining physics, firstly, I would have to mention that the early history of physics is interrelated with that of other sciences, maths and concepts. As we know, the first areas of physics to receive close attention were mechanics and the study of planetary motions. The great breakthrough in astronomy, another form of science, was made by Nicolaus Copernicus, who proposed the heliocentric model of the solar system that was later modified by Johannes Kepler, using observations by Tycho Brahe, into the description of planetary motions, an area of physics, that is still accepted today. Newton’s Three Laws of Motion are also famous in physics today. He arrived at his results of these laws, by inventing a form of entirely new branch of mathematics, calculus, which has become an essential tool in most branches of physics. Therefore, I have come to state that physics is considered as “a body of knowledge and as the practice that makes and transmits it. The growth of physics has brought not only fundamental changes in ideas about the material world, but also, through technology based on laboratory discoveries, a transformation of society.”
Uncertainty in Measurements
Because the nuraber of digits that are valid for any measurement is limited, the precision of all measuring devices is also limited. Every measurement is subject to uncertainty.
Causes of uncertainty:
1. temperature
2. magnetic fielRAB
3. parallax
4. carelessness
Chapter 3:
General Principles of Temporal Displacement
In chapter 3, we learned that displacement is the change in position of an object. Because this interests me I decided to enlighten you on the subject of Temporal Displacement. The TARDIS is a powerful machine that allows temporal displacement from within the space-time dimension. It is most important that the operator of the TARDIS have a fundamental understanding of temporal displacement (‘time travel’) if he or she is to understand and successfully pilot the TARDIS. There are only four laws of time travel, but first you must understand the Circular (linear) Theory of Time, which is the general theory of time that most events are regulated by. In this theory one is required to picture the space-time continuum as a ‘laser disk’, a circular plane with a starting point at the center. “The creation of the universe is dubbed Event One, and it is this that the center of the disc represents. At the boundary it is theorized that time runs backwarRAB and all event waves now head towarRAB Event One.” The term given to this process when the TARDIS dematerializes from one point in space-time and rematerializes in another. In effect, the TARDIS is skipping tracks, traveling to tracks long passed or journeying ahead of the event wave. Track skipping is really another name for temporal displacement or ‘time travel’.
Chapter 4:
“You sit in an elevator like cart which goes all the way to the top of the ride. It goes forward a little…and then swoosh you’re dropped down.”
Freefall
As you dropped down the tracks all the potential energy that was stored up when you ascended up in the elevator turns into kinetic energy, which is energy in motion. This is an example of the Law of Conservation of Energy. However, because this is a “real world” example all the potential energy does not convert into kinetic energy due to some lost to friction.
While falling you yourself will be in free fall where there is a weightlessness feeling. Free fall is motion determined solely by gravitational forces. This is due to the fact that the only force acting on you is gravity. This acceleration is known as the acceleration due to gravity, represented by the letter g, which is equal to 9.8 m/s2 or 32 ft/s2. The acceleration due to gravity differs on each planet because of the different gravitational strength. On Mars the g is 3.3 m/s2. On Jupiter the g is 25.6 m/s2. On the moon the g is 1.67 m/s2.
As we know, the speed at which an object is falling during free fall can be determined, when started at rest, by this equation: v= g * t
The distance an object has traveled during free fall can be determined, when started at rest, by this equation: s = 1/2g(t)2
A free falling object, such as a sky diver, can reach a speed of more than 118 miles per hour however there is a certain speed, the terminal velocity, where you can’t going any faster due to air resistance. A parachutist experiences free fall for a brief period before the parachute opens, but the force of air resistance against the person’s body soon becomes significant and he or she no longer falls freely.
Chapter 7:
Pendulum Rides
Pendulum rides are a little like the swing sets you might remeraber from your childhood. Swings give you a feeling of flying in a controlled manner. You pump your legs to provide enough force to increase the height of the swing’s arc, and enjoy the increased velocity of the downward swing. When you stop pumping, the swing gradually slows and then stops.
Some people wonder what causes the feeling of “weightlessness” on pendulum rides.
Riders often experience near-weightlessness as they approach the top of a pendulum ride. “If the ride is the type that makes a complete 360-degree circle, they experience a feeling of complete weightlessness.”
“Feelings of weightlessness are not due to a decrease in forces of gravitation; people do not feel forces of gravity. What you feel is the force of a seat pushing on your body with a force to counteract gravity’s downward pull. A 180-pound person at rest in his office chair experiences the seat pushing upwarRAB on his body with a force of 180 pounRAB.” Yet at the top of a pendulum ride, the same 180-pound person will feel less than this normal sensation of weight. At the very top of the pendulum ride, riders begin to fall out of their seats. Since a 180-pound person is no longer in full contact with his seat, the seat is no longer pushing on him with 180 pounRAB of force. Thus, the rider has a sensation of weighing less than his normal weight.
Chapter8:
Space Sniffles
The second set of weightlessness effects involves body fluiRAB. Within minutes of arriving in a weightless environment, a traveler’s neck veins begin to bulge, and the face begins to fill out and become puffy. As fluid migrates to the chest and head, sinus and nasal congestion results. This stuffiness, which is much like a cold on Earth, continues for the entire flight, except during heavy exercise, when the changing fluid pressures in the body relieve the congestion temporarily. Even the senses of taste and smell are altered; spicy food retains its appeal best. “In the early days of space flight, doctors feared that the chest congestion might be dangerous, much as pulmonary edema is to cardiac patients; fortunately, this has not been the case.
Another set of effects caused b weightlessness relates to muscle and bone. People who travel in space for any length of time come home with less of both. During weightlessness, the forces within the body’s structural elements change dramatically. Because the spine is no longer compressed, people grow taller (two inches or so). The lungs, heart and other organs within the chest relax and expand. Similarly, the weights of the liver, spleen, kidneys, stomach and intestines disappear. Disorientation, fluid redistribution, and muscle and bone loss are not the only consequence of weightlessness. Other body systems are affected directly and indirectly. One example is the lung.
The effects of space travel on the body reserable some of the conditions of aging. Studying astronauts’ health may help us understand weightlessness and the Human Body.
Chapter 6:
Sine, Cosine, and Tangent
Sine is one of several critically important concepts in trigonometry, a branch of mathematics that deals with triangles, especially right-angled triangles. “It is customary to designate one of the acute angles in a right triangle as theta. The sine of the angle theta is a ratio: the length of the side opposite theta, divided by the length of the hypotenuse. The value of sine depenRAB on--- or is a function of—the size of the angle theta; the sine is therefore called a trigonometric function. Because the sine can also be derived from a circle, with a radius of one unit, it is also called a circular function. In usage, sine is always abbreviated as sin.
In any right-angled triangle, the cosine of an acute angle theta is a ratio: the length of the side adjacent to theta, divided by the length of the hypotenuse.
In the drawing above (left) the adjacent side is a and the hypotenuse is b, so the cosine of theta, abbreviated cos theta, is a/b. The cosine can also be derived from a circle with unit radius, and is therefore often called a circular function. “The law of cosines is a relation expressing one side of a triangle in terms of the remaining two sides and the opposite angle: a2 = b2 + c2- 2bc cos A; a, b, and c are sides of the triangle, and A is the angle opposite to side a. The cosine is widely used in science and mathematics.
In geometry, a straight line is said to be tangent to a curve when the line touches the curve at a single point. A tangent plane, correspondingly, is a plane that touches a surface at a single point, and tangent circles are circles that have a single point in common along their perimeters.
In trigonometry, the tangent is one of six ratios of the sides of a right triangle that serve as circular functions. It is the ratio of the length of the side opposite to acute angle to that of the side adjacent to the acute angle. In Cartesian coordinates, the tangent of the angle i
Is the ratio of the v-coordinate divided by the x-coordinate of point P (x, y) on the circumference of a unit circle, where the radius makes an angle i with the positive x-axis.
Chapter 5:
Kinematics & Dynamics
Kinematics is the branch of physics concerned with the description of motion. “The standard way to describe motion is to give the position of an object as a function of time. In one dimension, the displacement x from the origin is given in terms of the time t after zero time. The velocity v is the time rate of change of position.” Similarly, acceleration is the time rate of change of velocity. When objects move in three dimensions, the speeRAB and accelerations in each perpendicular direction can be treated separately, since both velocity and acceleration are vectors.
Dynamics is a part of the field of mechanics, which is a branch of physical science. Dynamics deals with the motion of objects and material under the influence of applied forces. It is one of the oldest and most basic branches of physics. “The fundamentals of classical dynamics were stated by Isaac Newton in his book Principia Mathematica Philosophiae Naturalis (1686). Newton’s laws of motion and gravitation were sufficient to describe almost all motion of practical interest for over two centuries until 1905, when Albert Einstein proposed his theory of relativity. Einstein’s mechanics extended Newtonian dynamics, to include motion at speeRAB approaching that of light.” Later, Max Planck, Werner Heisenberg, and others developed quantum mechanics, to describe motion on a subatomic scale.
Bibliography
1. 1998 Grolier Interactive Inc. Free fall, Trigonometry, Newton’s Laws of Motion.
2. Uncertainty in Measurements Page. http://www.glynn.k12.ga.us/%7Empmcveigh/COURSE/PHYSICS/NOTES/uncertainty.html
3. More About Sig. Digs. Hamlet Project. http://www.krellinst.org
4. General Principles of Temporal Displacement. http://www.tardis.ed.ac.uk/~abr/drwho/type40/sec2.html
5. Amusement Park Physics. The Annenberg/CPB Project Exhibits Collection. http://www.learner.org
6. Weightlessness and The Human Body. Scientific American. http://www.sciam.com/1998/0998issue/0998white.html
7. Paul Zitzewitz, Robert Neff & Mark DaviRAB (1995). Merrill Physics: Principles and Problems. Ohio: Glencoe/McGraw-Hill
As I researched, I found many different definitions of Physics, some being very complex and others being simple and to the point. In defining physics, firstly, I would have to mention that the early history of physics is interrelated with that of other sciences, maths and concepts. As we know, the first areas of physics to receive close attention were mechanics and the study of planetary motions. The great breakthrough in astronomy, another form of science, was made by Nicolaus Copernicus, who proposed the heliocentric model of the solar system that was later modified by Johannes Kepler, using observations by Tycho Brahe, into the description of planetary motions, an area of physics, that is still accepted today. Newton’s Three Laws of Motion are also famous in physics today. He arrived at his results of these laws, by inventing a form of entirely new branch of mathematics, calculus, which has become an essential tool in most branches of physics. Therefore, I have come to state that physics is considered as “a body of knowledge and as the practice that makes and transmits it. The growth of physics has brought not only fundamental changes in ideas about the material world, but also, through technology based on laboratory discoveries, a transformation of society.”
Uncertainty in Measurements
Because the nuraber of digits that are valid for any measurement is limited, the precision of all measuring devices is also limited. Every measurement is subject to uncertainty.
Causes of uncertainty:
1. temperature
2. magnetic fielRAB
3. parallax
4. carelessness
Chapter 3:
General Principles of Temporal Displacement
In chapter 3, we learned that displacement is the change in position of an object. Because this interests me I decided to enlighten you on the subject of Temporal Displacement. The TARDIS is a powerful machine that allows temporal displacement from within the space-time dimension. It is most important that the operator of the TARDIS have a fundamental understanding of temporal displacement (‘time travel’) if he or she is to understand and successfully pilot the TARDIS. There are only four laws of time travel, but first you must understand the Circular (linear) Theory of Time, which is the general theory of time that most events are regulated by. In this theory one is required to picture the space-time continuum as a ‘laser disk’, a circular plane with a starting point at the center. “The creation of the universe is dubbed Event One, and it is this that the center of the disc represents. At the boundary it is theorized that time runs backwarRAB and all event waves now head towarRAB Event One.” The term given to this process when the TARDIS dematerializes from one point in space-time and rematerializes in another. In effect, the TARDIS is skipping tracks, traveling to tracks long passed or journeying ahead of the event wave. Track skipping is really another name for temporal displacement or ‘time travel’.
Chapter 4:
“You sit in an elevator like cart which goes all the way to the top of the ride. It goes forward a little…and then swoosh you’re dropped down.”
Freefall
As you dropped down the tracks all the potential energy that was stored up when you ascended up in the elevator turns into kinetic energy, which is energy in motion. This is an example of the Law of Conservation of Energy. However, because this is a “real world” example all the potential energy does not convert into kinetic energy due to some lost to friction.
While falling you yourself will be in free fall where there is a weightlessness feeling. Free fall is motion determined solely by gravitational forces. This is due to the fact that the only force acting on you is gravity. This acceleration is known as the acceleration due to gravity, represented by the letter g, which is equal to 9.8 m/s2 or 32 ft/s2. The acceleration due to gravity differs on each planet because of the different gravitational strength. On Mars the g is 3.3 m/s2. On Jupiter the g is 25.6 m/s2. On the moon the g is 1.67 m/s2.
As we know, the speed at which an object is falling during free fall can be determined, when started at rest, by this equation: v= g * t
The distance an object has traveled during free fall can be determined, when started at rest, by this equation: s = 1/2g(t)2
A free falling object, such as a sky diver, can reach a speed of more than 118 miles per hour however there is a certain speed, the terminal velocity, where you can’t going any faster due to air resistance. A parachutist experiences free fall for a brief period before the parachute opens, but the force of air resistance against the person’s body soon becomes significant and he or she no longer falls freely.
Chapter 7:
Pendulum Rides
Pendulum rides are a little like the swing sets you might remeraber from your childhood. Swings give you a feeling of flying in a controlled manner. You pump your legs to provide enough force to increase the height of the swing’s arc, and enjoy the increased velocity of the downward swing. When you stop pumping, the swing gradually slows and then stops.
Some people wonder what causes the feeling of “weightlessness” on pendulum rides.
Riders often experience near-weightlessness as they approach the top of a pendulum ride. “If the ride is the type that makes a complete 360-degree circle, they experience a feeling of complete weightlessness.”
“Feelings of weightlessness are not due to a decrease in forces of gravitation; people do not feel forces of gravity. What you feel is the force of a seat pushing on your body with a force to counteract gravity’s downward pull. A 180-pound person at rest in his office chair experiences the seat pushing upwarRAB on his body with a force of 180 pounRAB.” Yet at the top of a pendulum ride, the same 180-pound person will feel less than this normal sensation of weight. At the very top of the pendulum ride, riders begin to fall out of their seats. Since a 180-pound person is no longer in full contact with his seat, the seat is no longer pushing on him with 180 pounRAB of force. Thus, the rider has a sensation of weighing less than his normal weight.
Chapter8:
Space Sniffles
The second set of weightlessness effects involves body fluiRAB. Within minutes of arriving in a weightless environment, a traveler’s neck veins begin to bulge, and the face begins to fill out and become puffy. As fluid migrates to the chest and head, sinus and nasal congestion results. This stuffiness, which is much like a cold on Earth, continues for the entire flight, except during heavy exercise, when the changing fluid pressures in the body relieve the congestion temporarily. Even the senses of taste and smell are altered; spicy food retains its appeal best. “In the early days of space flight, doctors feared that the chest congestion might be dangerous, much as pulmonary edema is to cardiac patients; fortunately, this has not been the case.
Another set of effects caused b weightlessness relates to muscle and bone. People who travel in space for any length of time come home with less of both. During weightlessness, the forces within the body’s structural elements change dramatically. Because the spine is no longer compressed, people grow taller (two inches or so). The lungs, heart and other organs within the chest relax and expand. Similarly, the weights of the liver, spleen, kidneys, stomach and intestines disappear. Disorientation, fluid redistribution, and muscle and bone loss are not the only consequence of weightlessness. Other body systems are affected directly and indirectly. One example is the lung.
The effects of space travel on the body reserable some of the conditions of aging. Studying astronauts’ health may help us understand weightlessness and the Human Body.
Chapter 6:
Sine, Cosine, and Tangent
Sine is one of several critically important concepts in trigonometry, a branch of mathematics that deals with triangles, especially right-angled triangles. “It is customary to designate one of the acute angles in a right triangle as theta. The sine of the angle theta is a ratio: the length of the side opposite theta, divided by the length of the hypotenuse. The value of sine depenRAB on--- or is a function of—the size of the angle theta; the sine is therefore called a trigonometric function. Because the sine can also be derived from a circle, with a radius of one unit, it is also called a circular function. In usage, sine is always abbreviated as sin.
In any right-angled triangle, the cosine of an acute angle theta is a ratio: the length of the side adjacent to theta, divided by the length of the hypotenuse.
In the drawing above (left) the adjacent side is a and the hypotenuse is b, so the cosine of theta, abbreviated cos theta, is a/b. The cosine can also be derived from a circle with unit radius, and is therefore often called a circular function. “The law of cosines is a relation expressing one side of a triangle in terms of the remaining two sides and the opposite angle: a2 = b2 + c2- 2bc cos A; a, b, and c are sides of the triangle, and A is the angle opposite to side a. The cosine is widely used in science and mathematics.
In geometry, a straight line is said to be tangent to a curve when the line touches the curve at a single point. A tangent plane, correspondingly, is a plane that touches a surface at a single point, and tangent circles are circles that have a single point in common along their perimeters.
In trigonometry, the tangent is one of six ratios of the sides of a right triangle that serve as circular functions. It is the ratio of the length of the side opposite to acute angle to that of the side adjacent to the acute angle. In Cartesian coordinates, the tangent of the angle i
Is the ratio of the v-coordinate divided by the x-coordinate of point P (x, y) on the circumference of a unit circle, where the radius makes an angle i with the positive x-axis.
Chapter 5:
Kinematics & Dynamics
Kinematics is the branch of physics concerned with the description of motion. “The standard way to describe motion is to give the position of an object as a function of time. In one dimension, the displacement x from the origin is given in terms of the time t after zero time. The velocity v is the time rate of change of position.” Similarly, acceleration is the time rate of change of velocity. When objects move in three dimensions, the speeRAB and accelerations in each perpendicular direction can be treated separately, since both velocity and acceleration are vectors.
Dynamics is a part of the field of mechanics, which is a branch of physical science. Dynamics deals with the motion of objects and material under the influence of applied forces. It is one of the oldest and most basic branches of physics. “The fundamentals of classical dynamics were stated by Isaac Newton in his book Principia Mathematica Philosophiae Naturalis (1686). Newton’s laws of motion and gravitation were sufficient to describe almost all motion of practical interest for over two centuries until 1905, when Albert Einstein proposed his theory of relativity. Einstein’s mechanics extended Newtonian dynamics, to include motion at speeRAB approaching that of light.” Later, Max Planck, Werner Heisenberg, and others developed quantum mechanics, to describe motion on a subatomic scale.
Bibliography
1. 1998 Grolier Interactive Inc. Free fall, Trigonometry, Newton’s Laws of Motion.
2. Uncertainty in Measurements Page. http://www.glynn.k12.ga.us/%7Empmcveigh/COURSE/PHYSICS/NOTES/uncertainty.html
3. More About Sig. Digs. Hamlet Project. http://www.krellinst.org
4. General Principles of Temporal Displacement. http://www.tardis.ed.ac.uk/~abr/drwho/type40/sec2.html
5. Amusement Park Physics. The Annenberg/CPB Project Exhibits Collection. http://www.learner.org
6. Weightlessness and The Human Body. Scientific American. http://www.sciam.com/1998/0998issue/0998white.html
7. Paul Zitzewitz, Robert Neff & Mark DaviRAB (1995). Merrill Physics: Principles and Problems. Ohio: Glencoe/McGraw-Hill