Science Midterm 2024

Key characteristics of science? 1. Physical universe 2. Limited domain 3. Tool 4. Scientific method What is a hypothesis? A prediction or an answer to a scientific question Why is a hypothesis not an educated guess? Educated guess means "I know but I don't know" which is an incorrect statement What are examples of scientific method questions? How does fertilizer affect plant growth? Why is my toaster not toasting anything? Why is your goal to prove yourself wrong? Because if you're always trying to prove yourself right then you'll become bias but if you're trying to prove yourself wrong then your tests will be based on genuine tests that will actually either agree with your hypothesis or disagree with it Difference between a theory and a hypothesis? Theory is a strong idea while a hypothesis is a new idea Why is a theory a strong idea? The theory has been tested multiple times and never proven wrong What is the relationship between theories and laws? Theories cannot become laws, theories can change, laws cannot change. Theories come from hypothesis, laws come from observations. What is the difference between civil and scientific laws? Civil laws dictate behavior, scientific laws describes "natural" What is the difference between mathematical and scientific "proof"? Between facts and evidence? Mathematical proof : if A=B and B=C then A=C. It's absolute and you can't test it and prove it wrong Scientific proof: Evidence, gathering information What are the lessons from the observations? 1. Never assume, always test 2. We can miss the most important observation when we believe there's nothing else to observe 3. Paying attention to the action and the non-action 4. Memories aren't always reliable so spending more time on it and learning it can help 5. You can miss the obvious observation by being distracted by what's not important 6. It's easy to miss something you're not looking for 7. To understant the difference between observations and inferences What does domain mean? Domini in Latin = Lord What is a mobius? Twisted loop with 1 side, 1 edge object What is an inference? Assumption based on an observation What is a celt? Found in celtic burial sites, stone, not evenly rounded What's an observation? The use of your 5 senses What is wrong about the Baloney System? 1. No pattern 2. No alignment with our counting system 3. Little to no corelation among different types of measurement 4. Variance 5. Measurements produce fractions 6. Really big and small numbers are hard to manage Who created the meter? Eratosthenes, 250 BC What's the rhyme for the SI System? "In 1793, in the fair city of Paris, the international system came to be" What is the "Golden Measurement"? Meter=equator to pole / 10 (7 times) Length Measures a straight line distance Volume Amount of space something takes up Mass How much stuff (amount of matter) How do you find 1 Liter? 1 meter / 10 = 1 deci x 1 deci x 1 deci = 1 deci cubed = 1 Liter What is the SI unit for weight? Newton, N What is the relationship between SI and Baloney System? 1 kg H2O = 2.2 lbs = 9.8N 9.8N/2.2 Ibs = XN/150 Ibs What is accuracy? Hitting your target It's a yes or no question No such thing as "more" or "less: What is precision? "How big is it?" Can be "more" or "less" What are counted numbers? Not measured numbers so there's no doubtful digit (ex. the amount of pencils on the table) What are defined numbers? Have no doubtful digits (ex. 60 minutes in an hour) When measuring, what do you want? Accuracy with maximum precision What does the location of the doubtful digit communicate? The precision of the target What do all measurement have? Doubtful digits Handbreadth 3 inches (length of your knuckles) Span Average length = 9 inches (thumb to pinkie) Shekels Measures weight (1 ounce of gold) Talent 3,000 shekels (75 pounds of gold) $3,000,000 Cubit 18 inches (length of your elbow to your tallest fingers) Inch The length of the kings thumb Foot Length of the king's foot Yard Length of the king's stride Gram 1 dm / 10 = 1 cm x 1 cm x 1 cm = 1 gram (1 cm cubed) What is tempature? Measures atomic motion = heat Celcius Boiling point is 100C, freezing is 0C, absolute zero is -273 Kelvin Boiling point is 373K, freezing is 272K, absolute zero is 0K Pounds Baloney system for weight Vectors Arrows that show direction and magnitude Magnitude The size Force A push or pull exerted on an object that can cause it to change it's motion Net Force All forces acting on an object Dynamic Equlibrium Net force = 0, it's at a constant velocity so it is moving Static Equilibrium Net force = 0, it's not moving Velocity Describes motion (speed and direction) Speed How fast an object is moving Acceleration Any change in motion, Net force > 0 Interia Resist change in motion Frame of Reference Comparison relative to something not moving Orbital motion Whenever an object is moving forward, and at the same time is pulled by gravity toward another object Coriolis effect Looks like objects curve but they're actually going in a straight line and we're the ones moving Who is Aristotle? Greece, 350 BC Was heavy on reasoning Didn't test his theories Natural places Who is Galileo? Italy, 1600s He would test and experiment Invented intertia Catholic church excommunicated him for his ideas Invented telescope Who is Sir Isaac Newton? England, 1700s Glorified for his ideas Created Calculus Built off of Galileo's ideas Believed physical universe was created by God What is Newton's First Law of Motion? If an object is at rest, it will stay at rest because it has interia. If an object is moving, it will continue moving (D.E.), unless an unbalanced force acts to change the motion (Net force > 0) What are the types of change in motion? Speed up Slow down Change direction (turn) What is constant speed? It has nothing to do with direction, it doesn't always mean something is in constant velocity, and net force > 0 What is constant velocity? Net force = 0, it is in dynamci equlibrium, and deals with direction and speed What is the equation for finding acceleration? a = 𝚫V/t m/s2 What is Newton's Second Law? a = F/m What is the relationship between force and acceleration? They are directly proportional to each other What does directionaly proportional mean? More friction, more mass, less friction, less mass What is the relationship between accleration and mass? They are inversely proportional to each other What does inversely proportional mean? More mass, less acceleration, less mass, more acceleration What is friction? A force that resists all motion Is friction and inertia the same? No, inertia resists change in motion while friction resists all motion What are the three types of friction? 1. Sliding friction 2. Static friction 3. Fluid friction Is there any friction when you're in free fall? (don't count air resistance) No friction, there's just gravity pulling the object down What is Galileo's reasoning? More mass means more inertia meaning more force needed to change the motion What is the acceleration due to gravity always on earth? 9.8 m/s2 What are the four equations when in free fall? 1. Vf = at 2. s = a t2 / 2 3. t = √2s/a 4. a = 2s/t2 What is terminal velocity? When an object in free fall reaches DE What is velocity doing when an object is in free fall? Velocity increases = speeding up Does the mass and weight change when in free fall? No, weight and mass do not change depending on where you are. They stay the same no matter where you are Who would hit terminal velocity first? Big or small kid? Why? Small kid, It takes less friction to equal out with the force of gravity What is Newton's 3rd Law? For every action, there's an equal and opposite reaction Who pulls harder in tug-of-war? Buff Bill or Skinny Minnie? Neither, they pull equally How can you win tug-of-war? Apply as much friction to the ground as possible. As well as friction between your hands and the rope Who pulls harder towards the moon? Earth or you? Neither, they both pull equally Who pulls harder? The Earth pulling on you or you pulling on the Earth? They both pull equal Why when you jump up and down you look like you're the only one who has a change in motion? Why doesn't the Earth move up as well? The Earth has way more mass than you so it's acceleration will be significantly smaller compared to you who has a smaller mass who will have a big amount of acceleration How does a rocket fly? Rocket pushes exhaust down, exhaust pushes rocket up What is a recoil? A reaction What are the types of friction? 1. Fluid friction 2. Static friction 3. Sliding friction Displacement Distance What does it mean when an object is in free fall? An object is dropping, there's no friction, just gravity acting on it What is momentum? Inertia of a moving object What are two factors that affect momentum? Mass and velocity What's the equation for momentum? mom = mv What is the relationsip between acceleration and time? Inversely proportional to each other (at) What is the relationship between acceleration and force? Directly proportional to each other (af) What is impulse? What is required to change momentum What is the relationship between force and time? Inversely proportional to each other (ft) What is a collision? Moving objects inevitably collide What are the two types of collisions? 1. Elastic 2. Inelastic What are the ways to increase momentum? 1. Bounce 2. Increase the impulse What are ways to decrease momentum? Collision into an unmovable object When collisions occur, what do they obey? Newton's Laws What is an anti-collision? Prevention of a moving object hitting another moving object What is the Law of Conservation of Momentum? In any collision, the total momentum before is the same as the total momentum after