Science 8 8-16 1st Quarter 1.pdf

SCIENCE REVIEWR Lesson 1: Scientific Method Traits of a Good Scientist Curiosity and Fascination Humility and Healthy Skepticism Positive attitude toward failure Open-mindedness...

SCIENCE REVIEWR Lesson 1: Scientific Method Traits of a Good Scientist Curiosity and Fascination Humility and Healthy Skepticism Positive attitude toward failure Open-mindedness Perseverance Self-confidence Intellectual Honesty Scientific Intuition Aptitude for serendipity Ethics Scientific Investigation 1. Observe - keen observation and inference. Uses your 5 senses. Observation - simple observation using your senses Inference - an explanation gathered from the data 2. Research - identifying problem, review existing records. ex. Go to the library, Reading related problems, review existing records, and consulting experts 3. Formulate Hypothesis - a tentative answer (not a certain answer) Null Hypothesis (Ho) - a hypothesis that says there is no significance or relationship between two variables Alternative Hypothesis (Ha) - a hypothesis that says that there is significance or a relationship between two variables 4. Test / Experiment - designing and testing experiment, make sure to check your variables a. Independent Variable - the variable that you manipulate and change b. Dependent Variable - the variable that is being observed or affected by the independent variable c. Constant Variable - the variable that stays the same throughout the entire experiment Fair Testing - changing one variable at a time Groups in an experiment: 1. Experimental Group - receives the tested independent Variable 2. Control Group - group in an experiment that does not receive changes a. Positive Control Group - involves conditions where a known response or effect is expected b. Negative Control Group - no response or effect is anticipated (kept constant) 5. Analyze - summarizing data. Visualizing data like graph, table, and diagram a. Qualitative Data - uses adjectives or attributes to describe the properties of a phenomenon b. Quantitative Data - uses specific numbers rather than attributes 6. Conclude - direct response to the problem. You will need to accept or reject your hypothesis. Scientific Method - systematic approach that uses scientific skills to explain phenomena and solve problems Hypothesis - it is a proposed answer to a scientific question based on initial pieces of evidence. Data Gathering - involves the collection of facts that may be recorded through observation Lesson 2: Introduction to Force Force - a push or pull in a specific direction Uses Newton (N) as its unit of force. 1 Newton = 1 kg m/s² Free-body diagram – used to visualize the force and moments applied Types of Force Contact Force – forces that act between two objects that are physically touching each other. Ex. Friction, Air Resistance, Tension, and applied force. Non-contact Force – forces that act without any physical touch. Ex. Gravity, magnetic and electrostatic force.  Lesson 3: Laws of Motion First Law of Motion - An object at rest stays at rest, and an object in motion stays in motion, with the same speed and direction... UNLESS acted upon by an UNBALANCED FORCE. (Objects will continue to do what they’re doing unless some other force acts on it.) Inertia – tendency of objects in motion to stay in motion and objects are rest to stay at rest. Net Force – total sum of all the forces combined. (If two forces are going in the same direction, simply add them together.) (If two forces are going in opposite directions, simply subtract them.) Second Law of Motion - Acceleration is directly proportional to the net force applied, and inversely proportional to the mass of the object. Acceleration (a) and Net Force (N) formula Force / Net Force = Newton (N) Acceleration = meters per second square (m/s²) mass = kilograms (kg) GRESA Method Example Question Given – the given values from the problem Required – what is being asked from the problem (acceleration = ?) Equation – formula required to solve the problem Solution – how you solved the problem Answer – your final answer to the question Mass – quantity that shows how much inertia an object has - no direction, uses kg Weight – a force and measured in newtons - weight = mass x gravity - g = 9.8 m/s² Third Law of Motion – Every action has an equal and opposite reaction  Lesson 4: Work, Power, Energy Work – a change in energy - work done by an object – loses energy (ex. Walking) - work done on an object – gains energy (ex. A chair being dragged) - force + objects move in the direction of applied force - work is being done when the force is going the same direction as the motion - W = Fd (Force x Displacement). Joules = N*m. (Joules = unit) Power – the rate at which work is done. (Quickly and slowly) - P = W/t (Work divided by time) - uses Watt. Watt = J/s Energy – ability to do work. Unit: Joules - when potential energy decreases, kinetic energy increases and vice versa - potential energy + kinetic energy = total mechanical energy Potential Energy – stored energy due to the position of an object Gravitational Potential Energy - energy which is related to gravity GPE = mgh (mass x gravitational acceleration x height) [(kg)(m/s^2)(m)] Kinetic Energy – energy of a moving object (square the velocity) Transformation of Energy – processes of converting energy into another form Total Mechanical Energy = Gravitational Potential Energy + Kinetic Energy Law of Conservation of Energy – energy can only be transferred not made or destroyed