Grade 10 Physics Study Guide PDF

Science is divided into two main branches: Living and nonliving things ---- the life sciences and the physical sciences. List the life sciences. 1. Biology 2. Zoology 3. Botany List the physical sciences. 1. Physics 2. Geology 3. Astronomy 4. Chemistry Define the l...

Science is divided into two main branches: Living and nonliving things ---- the life sciences and the physical sciences. List the life sciences. 1. Biology 2. Zoology 3. Botany List the physical sciences. 1. Physics 2. Geology 3. Astronomy 4. Chemistry Define the life sciences. 1. Biology : the study of life 2. Zoology: the study of animals, their structures, behaviors, habitats, etc.… (all things to do with animals) 3. Botany: it is a branch of biology, meaning the study of plants. Define the physical sciences. 1. Physics: it talks about the nature of basic things like, motion, forces, energy, matter, heat, sound, composition of atoms, etc.… 2. Geology: it is the study of earth , and its structure , substance , and its history 3. Astronomy: it is the study of everything beyond the earth’s atmosphere. ( like celestial objects) 4. Chemistry: it is the study of matter and its essence and substances. Define Natural philosophy. Study of unanswered questions about nature. Facts to remember! Physics is the most basic of all the sciences Much of science today is what used to be called natural philosophy. Biology is more complex than Chemistry, and involves matter that is alive Physics supports chemistry, which in turn supports biology. You can understand other sciences much better if you understand physics. When scientific findings in nature are expressed mathematically, they are easier to verify or disprove by experiment. Trial and error, experimentation without guessing, and accidental discovery account for much of the progress in science.  The success of science has more to do with an attitude common to scientists than with a particular method. This attitude is one of inquiry, experimentation, and humility. An object is in a state of equilibrium if the sum of the forces acting on it is zero. Who are considered or credited as the founders of the scientific method? Italian physicist Galileo Galilei and the English philosopher Francis Bacon What are the steps of scientific methods? 1. Recognizing/Identifying the problem 2. Make an educated guess (a hypothesis) about the answer. 3. Predict the consequences (results) of the hypothesis. 4. Perform experiments to test predictions. 5. Formulate the simplest general rule that organizes the main ingredients: hypothesis, prediction, and experimental outcome. ( checking the result) THE SCIENTIFIC ATTITUDE: A fact is a close agreement by competent observers who make a series of observations of the same phenomenon. A scientific Hypothesis is an educated guess that is not fully accepted until demonstrated by experiment. When hypotheses are tested over and over again and not contradicted, they may become laws or principles. Laws describe what will happen in a given situation as demonstrable by a mathematical equation Principle is used in science to mean the same thing as law. When a hypothesis is not scientific. It cannot be proven wrong, nor can it be proven right. It is speculation If a scientist finds evidence that contradicts a hypothesis, law, or principle, then the hypothesis, law, or principle must be changed or abandoned A scientific theory is a synthesis (placed together) of a large body of information that encompasses well-tested and verified hypotheses about certain aspects of the natural world. Scientific Hypotheses Before a hypothesis can be classified as scientific, it must link to a general understanding of nature and conform (follow) to a cardinal (basic) rule. The rule is that the hypothesis must be testable. It is more important that there be a way of proving a hypothesis wrong than there is a way of proving it correct. To determine whether a hypothesis is scientific or not, look to see if there is a test for proving it wrong. Which of these is a scientific hypothesis? A. Atoms are the smallest particles of matter. B. The universe is surrounded by a second universe, the existence of which cannot be detected by scientists. C. Albert Einstein was the greatest physicist of the 1900s. Science, Technology, and Society. Science and technology are different. Define science and technology. 1. Science : a method of answering theoretical questions 2. Technology: method of solving practical problems. Facts for science and technology: Science has to do with discovering facts and relationships between observable phenomena in nature and with establishing theories that organize and make sense of these facts and relationships. Technology has to do with tools, techniques, and procedures for putting the findings of science to use. True and False Science and technology are different (True) Science and technology are human enterprises (True) Technologists specifically set out to design, create, or build something for the use and enjoyment of humans (True) Many people blame technology itself for widespread pollution, resource depletion, and even social decay (True) That blame placed on technology often obscures its promise (True) Technology promises a cleaner and healthier world. (True) Science and technology make up a larger part of our everyday lives than ever before (True) Humans now have much more influence over nature’s delicate balance (True) The scientific way of thinking becomes vital to society as new facts are discovered (True) Technology depends on science and society depends on technology (True) The traditions of science are relatively recent (True) The theories of science are not fixed, but rather they evolve as they go through stages of redefinition and refinement (True) Progress in our age is much quicker than it was thousands of years ago (True) A truly educated person is knowledgeable in both arts and science. (True) The net force on an object changes its motion (True) SCIENCE, ART, AND RELIGION. The domains of science, art, and religion are different, even though they overlap. Science is mostly concerned with discovering and recording natural results and phenomena Arts are concerned with the values and cultures of human interactions. Religion is concerned with soul, spirit, source, purpose, and meaning of everything The domain of science is natural order The domain of religion is nature’s purpose. Science and religion complement each other rather than contradict each other. Science and art can be used to better understand each other FORCE A force is a push or pull A force is needed to change an object’s state of motion The combination of all forces acting on an object is called the net force The scientific unit of force is called newton, abbreviated N. Unit to measure weight is pound Unit to measure mass is kilogram MECHANICAL EQUILIBRIUM Mechanical equilibrium is a state of wherein no physical changes occur; it is a state of steadiness Whenever the net force on an object is zero, the object is said to be in the mechanical equilibrium This is known as the equilibrium rule. Express the mechanical equilibrium mathematically. ∑F=0 The ∑ stands for “the sum of” and F stands for “forces” Support force is the upward force that balances the weight of an object on a surface. It is often called normal force For an object at rest on a horizontal surface, the support force must equal to the object’s weight When you are standing on a scale, the support force and your weight have the same magnitude When you step on a scale, two forces act on the scale; one force is the downward pull of gravity, your weight, and the other is upward support force of the floor These forces compress a mechanism (a spring) that is adjusted to show your weight Equilibrium: is a state of no change For an object at rest on a horizontal surface, the support force equal to? Equals 0 What is the net force on a bathroom scale when a 110 pound person stands on it?  Weight of the person: 110 pounds (downward force)  Force exerted by the scale: 110 pounds (upward force)  Net force: 0 pounds (equilibrium) Suppose you stand on two bathroom scales with your weight evenly distributed between the two scales. What is the reading on each of the scales? What happens when you stand with more of your weight on one foot than the other? If you stand on two bathroom scales with your weight evenly distributed between them, each scale will read half of your total weight. For example, if you weigh 200 pounds, each scale would show a reading of 100 pounds. When you stand with more of your weight on one foot than the other, the readings on the scales will change accordingly When an object isn’t moving, it is in equilibrium An object moving at constant speed in a straight line path is also in state of equilibrium Once in motion, if there is no net force to change the state of motion, it’s in equilibrium. Objects at rest said to be in static equilibrium Objects moving at a constant speed in a straight line path are said to be in dynamic equilibrium. Dynamic meaning: constant change Static meaning: lacking inaction, or change Vector Quantities Vector quantities have both magnitude and direction. Examples include: 1. Displacement: The distance and direction from a starting point to an endpoint. 2. Velocity: Speed in a given direction (e.g., 60 mph north). 3. Acceleration: The rate of change of velocity in a specific direction. 4. Force: A push or pull in a specific direction (e.g., 10 N to the east). 5. Momentum: The product of mass and velocity, which has both magnitude and direction. Scalar Quantities Scalar quantities have only magnitude, without direction. Examples include: 1. Distance: The total path length traveled, regardless of direction (e.g., 50 miles). 2. Speed: The rate of change of distance (e.g., 30 mph). 3. Mass: The amount of matter in an object (e.g., 70 kg). 4. Temperature: A measure of thermal energy (e.g., 25°C). 5. Energy: The capacity to do work (e.g., 100 joules).