•Remember you can only have one independent variable in an experiment.(The thing you are testing and change). The independent variable goes on the x-axis when graphed. •All other parts of the experiment must remain the same (Constants) •The result you MEASURE is called the Dependent variable. The dependent variable goes on the y axis when graphed. Amusement Park Forces Physics 8.6a- Demonstrate and calculate how unbalanced forces change the speed and direction of an objects motion. Activities: Gizmo: Force and Fan Carts Lab: Car ramps (clay on string, and added weight to car) Lab: Newton’s Cart lab: Pennies in film canister and you burned the string What is a Force? FORCE = Any push or pull which causes something to move or change its speed or direction What is a Force? Forces can be BALANCED or UNBALANCED Balanced forces are equal in size and opposite in direction unbalanced forces are not equal in size and/or opposite in direction. If the forces on an object are UNBALANCED, we say a NET force results. Amusement Park Forces Friction is a Resistance Force Friction = A force that opposes or slows down motion Caused by the physical contact between moving surfaces The amount of friction depends upon the kinds of surfaces and the force pressing the surfaces together Changes motion into heat If you have 30N of force pulling left and another 20N of force pushing left, what is the total amount of force and in which direction? 50 N to the Left. What would be the best description of the net force between a woman and the chair she is sitting in? 0N – because the forces are balanced What is the net force on the box below? 5N right Luis pushes a toy race car down the floor to the left with 5N of force. Jonathon then pushes the race car in the same direction with another 6N of force. Which direction did the race car move and with how much force? 11 N left What is Friction? What are some ways athletes uses friction? Forces affect Motion: • • • • • • They can make objects start moving. They can make objects move faster. They can make objects move slower. They can make objects stop moving. They can make objects change direction. They can make objects change shape. Physics 8.6b- Differentiate between speed, velocity and acceleration Activities: -Motion detector Lab -Catch the Cheetah graph matching What is Motion? Motion: A change in position of an object compared to a reference point Motion involves all of the following: What is Motion? Speed The rate of change in position Speed = distance ÷ time or Distance Time Speed A ladybug crawls a distance of 50 centimeters in 20 seconds. What is the ladybug’s average speed? Speed = distance ÷ time or Distance Time 50/20 = 2.5 cm/sec What is Motion? Velocity Speed plus direction Example: 50 km/hour north What is Motion? Acceleration The rate of change in velocity Positive acceleration = speeding up Negative acceleration = slowing down (decelerate) Interpret The Graph Below: The graph shows an object which is not moving (at rest). Interpret The Graph Below: a b The objects are moving at a constant velocity- a is moving faster than b because it has a greater slope Interpret The Graph Below: an object moving with constant velocity towards you Interpret The Graph Below: Curve line up shows acceleration Interpret The Graph Below: Curve lines up show acceleration –in Red and Deceleration in black Interpret The Graph Below: The graph shows that the objects velocity does not change as time passes. It shows constant velocity. Interpret The Graph Below: The graph shows that the objects velocity is increasing as time passes – it is accelerating. 8.6c-Investigate and describe application of Newton’s Laws of Motion Activities: -Lab Stations- roller coaster, film canister rockets, crash car with toy doll, and putting golf balls - Force, mass and acceleration of a BB and marble -Newton’s Cart Lab- First Law(Law of Inertia): An object at rest stays at rest or an object in motion, stays in motion (in the same direction/at the same speed) unless acted upon by an unbalanced force Inertia The tendency of an object to resist any change in its motion The greater the mass the greater the inertia The greater the speed the greater the inertia Examples of Newton’s 1st Law (do not copy) a) car suddenly stops and you strain against the seat belt b) when riding a horse, the horse suddenly stops and you fly over its head c) the magician pulls the tablecloth out from under a table full of dishes d) the difficulty of pushing a dead car e) lawn bowling on a cut and rolled lawn verses an uncut lawn Second law (Law of Force and Acceleration): The greater the force, the greater the acceleration The greater the mass, the greater the force needed for the same acceleration Calculated by: F = ma (F = force, m = mass, a = acceleration) Examples of Newton’s 2nd Law of Force and Acceleration (do not copy) a) hitting a baseball, the harder the hit, the faster the ball goes b) accelerating or decelerating a car c) The positioning of football players - massive players on the line with lighter (faster to accelerate) players in the backfield d) a loaded versus an unloaded truck Third law (Law of ActionReaction): For every action force, there is an equal and opposite reaction force. (Forces are always paired) Examples of Newton’s 3rd Law a)rockets leaving earth b)guns being fired c) two cars hit head on d) jumping out of a boat onto the dock Examples of Newton’s 3rd Law Potential Energy (PE)- Energy of position Kinetic Energy (KE)- Energy of motion Always check the margin titles of any graph to help you answer questions. Moving at a steady Rate or pace Time (sec) Moving at a steady Rate or pace Distance (m) Speed (m/s) Speeding up or accelerating Not moving Time (sec) Chemistry 8.5a- Describe the structure of atoms, including the masses, electrical charge and locations, of protons, and neutrons in the nucleus and electrons in the electron cloud. Activities: -Building atom models - Drawing Bohr models and building the periodic table Name of subatomic particle proton electron neutron Charge of Particle Where it is found Size/mass Positive (+) inside the nucleusidentifies the atom 1 atomic mass unit Negative (-) in electron cloud / orbiting around nucleusdetermines reactivity of element Neutral (0) inside the nucleus- just adds mass/weight Almost zero 1/1836 amu (very small!) 1 atomic mass unit 3 of 4 8.5b- Identify that protons determine an elements identity and valence electrons determine its chemical properties including reactivity. Elements in the same group have similar properties and reactivity because they have the same valence. A stable valence is 8 for all elements except Hydrogen and Helium. A stable valence for these elements is 2. Group 18 is unreactive because all elements have a full valence shell!! As you move down the group elements become more reactive because they have more electron energy levels. The electrons are farther away from the nucleus. 8.5c-interpret the arrangement of the periodic table, including groups and periods, to explain how properties are used to classify elelments Chemical Reactions 8.5e- investigate how evidence of chemical reactions indicate that new substances with different properties are formed. Activity: Lab: Evidence of chemical reactions. Chemical Property- ability of an element or compound to react with another substance. Key words: oxidation, reactivity, flammability Clues that indicate a chemical reaction: 1.The production of a gas. Evidence: bubbles, odor 2.A Change in temperature (can be an increase or decrease) 3.Production of a precipitate(makes a solid, often looks like a powder) 4.A color change- Clear + Clear = different color 8.5d- Recognize that chemical formulas are used to identify substances and determine the number of atoms of each element in chemical formulas containing subscripts. What elements are in this compound? Copper, Sulfur, Oxygen How many atoms of each? Copper=2, Sulfur=2, Oxygen=8 Total number of atoms 12 Chemistry 8.5f- Recognize whether a chemical equation containing coefficients is balanced or not and how that relates to the law of conservation of mass Activities: -Build me balance me -Balancing equations worksheets The Law of Conservation of Mass • States that matter can neither be created nor destroyed. – Atoms do not disappear in a chemical reaction! – they rearrange themselves into the new substances (products). • Equations have to be balanced with coefficients (representing the # of molecules) in order to support this law. – The # of atoms of each element must be the same on both sides of the equation! – Multiply the coefficient by the subscript to calculate number of atoms. Photosynthesis Equation Example: H20 + C02 C6H1206 + 02 unbalanced 6H20 + 6C02 C6H1206 + 602 balanced H= 12 O=12 + 6 = 18 C=6 C=6 H= 12 O=6 + 12 = 18 Astronomy 8.8a- Describe components of the universe including stars, nebulae, and galaxies, and use models such as the Hertzsprung-Russell diagram for classification. 8.8b. Recognize that the Sun is a medium sized star near the edge of a disc-shaped galaxy of stars and that the Sun is many thousands of times closer to Earth than any other star. 8.8c. Explore how different wavelengths of the electro-magnetic spectrum such as light and radio waves are used to gain information about distances and properties of components in the universe. 8.8d- Model and describe how light years are used to measure distances and sizes in the universe. Astronomy Notes Image From: http://www.astronomy-pictures.net/spiral_galaxy.jpg; 1 of 11 Stars • An object made of gas that gives off energy – mainly hydrogen – helium The Sun • • • • medium in size & life span compared to other stars primary energy source for all processes on Earth much closer to Earth than any other star! about 4 ½ billion years old H-R Diagram: Shows the relationship between color, temperature, magnitude & size of stars. Magnitude • Color = temperature • Magnitude = how bright • Our Sun is a main sequence star. 2 of 11 Black Dwarf Nebula 1. Large cloud of gas & dust where stars form. 2. Gravity pulls 4. Outer layers 5. Collapses material into a come off sphere that to just its 3. Expands becomes core dense, hot Explodes! & ignites. 3 of 11 4 of 11 Galaxy • A large grouping of stars in space. • 3 types 1. Spiral – bulge in center & distinctive spiral arms • • Example: Our galaxy, The Milky Way Our solar system is located within an arm 2. Elliptical – spherical or elongated 3. Irregular 1 2 3 Light Year A measure of how long it takes light to travel through space in one year. Image From: http://uniqhorns.com/images/milkyway.gif; Definition: www.thefreedictionary.com 9 of 11 10 of 11 Electromagnetic Spectrum The range of all the waves that can travel through matter as well as empty space. R O Y G B I V Scientists use different portions of the spectrum to learn about the universe. Ex: light waves can tell us what elements stars are made & if they are moving away or towards other objects. Image From: http://www.lcse.umn.edu/specs/labs/images/spectrum.gif Definition: www.thefreedictionary.com Space Cycle Notes Created by Harris Middle School 8.7b- demonstrate and predict the sequence of events in the lunar cycle 8.7c- Relate the position of the moon and Sun to their effect on ocean tides 8.7a- Model and illustrate how the tilted Earth rotates on its axis, causing day and night and revolves around the Sun causing changes in the seasons. Moon 7 of 11 • A natural satellite of a planet. • The outer planets have many of them! Image From: http://sos.noaa.gov/images/Solar_System/moon.jpg; Definition: www.thefreedictionary.com Lunar Cycle Full moon: all of surface facing Earth is illuminated (= lit) by the Sun New moon: moon is between Earth & Sun, so lit portion is facing away from Earth Waxing moon: lit portion “growing” Waning moon: lit portion “decreasing” Gibbous moon: larger than ½ Crescent moon: smaller than ½ Tides Tide = daily rise & fall in ocean water level • high and low tides occur twice daily • high tides are caused by the gravitational pull of the moon & sun, causing the ocean water to “bulge” away from the Earth • the moon has a greater impact because it is closer High tide occurs on the side facing the moon, but it also occurs on the opposite side. This is because the moon is also pulling the Earth away from the water on the other side. Low Tide Tidal bulge High Tide High Tide Low Tide Gravitational pull of the moon moon and sun pull together = largest tides moon and sun pull against each other = weakest tides Rotation vs. Revolution Rotation: • spin of object on its axis • rotates counter-clockwise = west to east = why sun appears to rise in the east and set in the west • for Earth = 24 hrs. =1 day • responsible for day vs. night Revolution: • also called an orbit • path of one object around another • Earth around sun ≈ 365 days = 1 year • moon around Earth ≈ 1 month The Earth is tilted on its axis by 23.5.° As a result, the hemisphere that is tilted toward the sun receives more direct sunlight = more heat. • causes longer daylight hours • hotter temperatures = summer! The hemisphere tilted away from the sun experiences winter. The TILT is the reason for seasons! For the Northern Hemisphere! = least daylight hours = most daylight hours = Equal hours of day and night Weather & Climate Unit Notes 8.10a- recognize that the Sun provides the energy that drives convection within the atmosphere and oceans, producing winds and ocean currents 8.10b- identify how global patterns of atmospheric movement influence local weather using weather maps that show high and low pressures and fronts 8.10c- identify the role of the oceans in the formation of weather systems such as hurricanes. Radiant Energy = from the Sun • Radiant energy drives changes in weather & creates different climates. – Weather changes from day to day. – Climate = a region’s general pattern of weather over a long period of time. • The equator receives the most direct angle of sunlight, creating the warmest climates. 1 of 11 2 of 11 Heating differences causes there to be different air masses. cool air (or water) is more dense than warm, so it sinks, creating currents by convection sun heats land and oceans by radiation land/ocean heats the air above it by conduction 3 of 11 Air movements create weather changes. Air mass = A body of air that has similar pressure, temperature, & humidity. •Different air mass pressures cause wind. • Air moves from high to low pressure areas. -Generally blow from poles toward equator -Weather often changes when air pressure changes -A front is where two air masses meet or collide 4 of 11 Warm air rises, decreasing the air pressure. 5 of 11 Land-Ocean Interactions Land heats up faster than water (= the ocean). – The air over the land will also heat quickly. – Warm air rises, starting a convection current. – This brings moist ocean air inland. • Ocean air holds a lot of water vapor. • Warm air can also hold more water vapor. – When air cools, it may no longer be able to hold on to all of the water vapor, forming clouds & precipitation. 6 of 11 Vocab ! 7 of 11 • Oceans can also influence weather in extreme ways, such as in the formation of hurricanes. = A low pressure tropical storm that forms over ocean water. • Oceans impact climate because they heat and cool slowly (=good insulator!). – Land near the ocean is often warmer in winter and cooler in summer, meaning inland climates differ from those near the ocean at the same latitude. • Oceans also impact climate via currents… 8 of 11 Current – movement of water in the ocean • Surface currents are affected by Winds Continental deflections Coriolis Effect – following the curve of the Earth as it rotates • Deep ocean currents are affected by Temperature differences (density) Salinity differences (density) 9 of 11 Movement of currents is constant and creates a “global conveyor belt” that transfers heat from one part of the Earth to another via water. 10 of 11 Ocean currents can bring in air of a different temperature that makes one area on Earth warmer than another at the same latitude – Example: Gulf Stream brings warm air into England, making it warmer than Nova Scotia, Canada at the same latitude. 11 of 11 L= Low pressure, cloudy and often rainy conditions H= High pressure, clear and pleasant skies. High means dry… When fronts move thru of extreme temperatures you often get thunderstorms. Cold fronts move from poles toward equator- have triangle flags (think icicles) Warm fronts move from equator toward poles- have half circle flags (think rising sun)