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Sci. Method & Flight
Sci. Method & Fligh
Question | Answer |
---|---|
In the Chocolate and the Scientific Method example, what was the independent variable? Why? | The number of candy bars because that is what Mrs.Brandt set different in each class or trial. |
In the Chocolate and the Scientific Method example, what was the dependent variable? Why? | The average quiz scores because they changed depending on the amount of candy bars promised. |
In the Chocolate and the Scientific Method example, what was the control group? Why? | 2nd hour. They were promised no candy. They had no changes from a normal quiz so the results of the other classes could be compared to them. |
In the Chocolate and the Scientific Method example, what were some constants? | Same quiz, same number of boys and girls in the classes, same age, same ability, same backgrounds |
In a data table for the Chocolate and the Scientific Method, what would go in the first column and why? | Trials or groups go first. Classes are the experimental groups in this experiment, so 2nd hour, 4th hour, 6th hour, 7th hour |
In a data table for the Chocolate and the Scientific Method, what would go in the second column and why? | Independent variable goes next, so number of candy bars in this experiment: 0,1,2,3 |
In a data table for the Chocolate and the Scientific Method, what would go in the third column and why? | Dependent variable goes last, so quiz scores: 70%, 80%, 90%, and 95% |
In the Chocolate and the Scientific Method example, what was the problem? | The scientific method always starts with a question or problem. Here it was Mrs. Brandt had low test scores and is wondering how to motivate students to get better scores. |
In the Chocolate and the Scientific Method example, what was the hypothesis? | If a class is promised more candy bars, the will score better on a quiz. |
In the Chocolate and the Scientific Method example, what was the conclusion? | The more candy bars promised, the better average scores the classes got on a quiz. |
What should Mrs. Brandt do at the end of this experiment and why? | She should repeat it and have others repeat it to remove bias and verify her results. |
Define Science | Science is a method for studying the natural world. Science looks for patterns in nature |
What is the name for the organized set of investigation procedures used by scientists the world over? | The Scientific Method |
List the steps of the scientific method in the order they are usually followed. | State the problem, gather information, form a hypothesis, test the hypothesis, analyze the data, draw conclusions |
A testable statement based on knowledge and observation | Hypothesis |
An if/then prediction about the outcome of an experiment | Prediction |
These are used to test a hypothesis by investigating the effect of one variable on another in a controlled environment | Experiments |
The variable in an experiment that is adjusted or set by the experimenter | Independent variable |
The variable in an experiment that changed depending on the value of the other variable. This is the one you measure and record in the experiment. | Dependent variable |
A variable that does not change in an experiment | Constant |
A group in an experiment that is used for comparison. No changes are made to it. | Control group |
This is when an experimenter sees what they expect to see in the results and builds scotomas to what is actually there. Because we know we do this we always repeat experiments multiple times and have others do them also to verify results | Bias |
This is a table used in an experiment for results. | Data Table |
This is an explanation based on many observations and investigations. It usually answers the question “Why?” | Scientific Theory |
This is a statement about something that always seems to be true. It usually answers the question “What?” | Scientific Law |
This is the application of science to help people in some way | Technology |
What is engineering? | Engineering is the field of study that applies scientific knowledge to build or make something. |
Scientists learn new information about the natural world through _______________. | Investigations |
Scientific investigations can involve ______, ________, ________. | Experiments, observations, and models |
____ are controlled investigations where one variable is changed to see how something else changes. | Experiments |
____ are made with your senses and recorded | Observations |
_____ are built to represent something hard to see or hard to explain | Models |
How is an observation different from and inference? | Observations are directly sensed (see, hear, taste...). An inference is a conclusion you make based on what you have sensed. |
The type of graph usually used when comparing the change in one variable with the change in another is a | Line Graph |
Which type of graph is used to "see" percentages? | circle or pie graph |
This type of graph is used when "counting" data. | A bar graph |
On a data table, the first column represents the | Groups or Trials |
On a data table, what variable is placed in the 2nd column? | The independent variable |
On a data table, where do we record the data gathered on the dependent variable? | The third column. |
When one variable increases as the other increases, and produces a straight line sloping up, we say they are ____proportional | directly |
If two variables are inversely proportional, one goes down as the other goes up, and the line produced slants | Downward |
Stored energy due to height and gravity | Potential Energy |
The energy of motion | Kinetic Energy |
State the Law of the Conservation of Energy | Energy cannot be created or destroyed; it only changes form |
The distance something travels per unit time | Speed |
Speed in a given direction | Velocity |
What type of quantity is velocity? Scalar or vector? | A vector quantity |
What makes velocity a vector quantity? | Vectors have both magnitude (size) and direction (e.g. 35mph west) |
These have both magnitude (size) and direction (e.g. 35 mph west) | Vectors |
The highest speed that can be reached by a falling object is its __________ | terminal velocity |
Terminal velocity is achieved when ____ | the force of gravity (pulling down on the object) is cancelled by the force of drag (air resistance pushing upward) |
What happens as a plane climbs? | Its speed decreases as kinetic energy (motion) is converted into potential energy (position). |
What happens as a plane dives? | Its speed increases as potential energy (position) is converted into kinetic energy (motion). |
What is force? | A push or a pull on an object |
What two things does a vector quantity have? | Magnitude and direction |
What are the 4 forces of flight, and in which direction do they act? | Lift pushes upward, weight (the force of gravity) pulls downward, thrust moves the plane forward, and drag resists it. |
What do we call the force every object in the universe exerts on every other object? | The Force of Gravity |
What is the acceleration of gravity on Earth for every object, not matter what it's size. | 9.8 m/sec^2. All things, big and small, fall at this rate if there is not air resistance! |
Why is the gravity of the earth noticeable, but not other objects like you or your pencil. | Gravity depends on mass and distance. The closer two things are the more gravitational force, and the bigger the more gravitational force. The earth is way more massive that us! |
The force of gravity on the mass of an object gives us its ________. | Weight |
What is the force that helps pilots overcome the weight of the plane? | Lift |
What is the direction of lift? | Lift is "up." Its force is perpendicular to the plane in level flight in the opposite direction of weight. |
"As airspeed increases, the pressure drops" is an example of what principle? | The Bernoulli principle |
According to the Bernoulli principle, where is the pressure highest on a plane's wing? | The pressure is highest under the wing because the air is traveling slower. |
According to the Bernoulli principle, what creates lift? | The pressure above the wing is lower than the pressure below the wing (because air moves faster on top to cover a bigger distance), causing a net force upward (lift). |
What is net force? | The sum of all the forces exerted on an object. |
State Newton's 1st Law of Motion | An object in motion will remain in motion, and an object at rest will remain at rest, unless acted on by an unbalanced force. OR If the forces are balanced, the object stays moving at a constant speed or stays stopped. |
What is inertia? | The tendency of an object to resist a change in motion |
Objects with more ___ have more inertia. | mass |
State Newton's 2nd Law of Motion | An unbalanced force will produce a proportional acceleration. (That is, if an unbalanced force acts on an object, it will accelerate) |
What is sometimes stated as "for every action there is an equal and opposite reaction? | Newton's 3rd Law of Motion |
In a jet plane what are the action/reaction forces? | The engine pushes exploding gases backwards, and the gases push the plane forwards (thrust). |
When a propeller plane takes off, what action/reaction is at work? | The propeller pushes air backwards, and the air pushes back on the propeller and attached plane, moving it forward (thrust). |
How is a parked plane an example of Newton's 1st Law of Motion? | A parked plane will not move unless an unbalanced force acts on it. |
How is a plane in the air an example of Newton's 1st Law of Motion? | A plane in the air will fly at a constant speed if all the forces on it are balanced. |
What force resists the movement of the airplane through the air? | Drag |
Why do engineers try to decrease drag? | Drag slows down the plane and lessens fuel economy. |
What is the direction of drag? | Drag acts along and opposed to the direction of flight. |
What is thrust? | Thrust is a push forward along the direction of drag. |
Apply Newton's third law to thrust from a propeller. | As the propeller pushes the air backwards, the air pushes the propeller and attached plane forward. We call this forward force thrust. |
What word is applied to the up and down movement of a plane's nose? | Pitch |
What word is used to explain the movement of a plane's nose right and left? | Yaw |
When the plane rotates around the axis in the middle of the plane, we call that a _______ | Roll |
What is stability? | Stability is the property of an airplane to return to its original position when disturbed by an outside force. |
What three design features help create stability? | 1. dihedral wings (the wing tips are higher than where it attaches to the plane's body. 2. triangular tail shape which helps control pitch like arrow feathers. 3. A balanced center of gravity so it flies level. |
When all forces acting on an object cancel each other, so the net force is 0, we call them this: | Balanced forces |
Unbalanced forces result in a net force in some _______. | direction |
When unbalanced forces act on an object, the object does this. | Accelerates in the direction of the net force. |
If a plane is flying level at a constant speed, what can you tell about the 4 forces of flight acting on it? | The forces are balanced. |
When a plane is flying level at a constant speed, which of Newton's Laws of Motion is at work? | Newton's 1st Law of Motion: an object in motion remains in motion in the same direction at the same speed unless acted on by unbalanced forces. |
If a pilot applies more throttle, and the plane accelerates, which of Newton's Laws is at work? | Newton's 2nd Law of Motion: A net force exerted on an object will produce a proportional acceleration. |
The rate of change in speed of an object (speeding up or slowing down) | Acceleration |
What is aspect ratio | It is the ratio of wingspan to chord (width) |
How do you calculate the aspect ratio of a wing? | wingspan/chord (width) |
What are the advantages of a larger aspect ratio? | More lift, easier to fly (more stable), shorter landing distance |
What are the advantages of a smaller aspect ratio? | Shorter wings to a point are more responsive. Fighter planes have small aspect ratios so they can turn quickly. |
What is wing loading? | It is the ratio of the planes gross weight to surface area of the wing |
How do you calculate wing loading? | weight/surface area of the wing (wingspan * chord) |
What happens to wing loading as wingspan increases? | It decreases |
What happens to wing loading as weight increases? | It increases |
How does increasing the horsepower of the engine in the design of a plane affect it ? | increases HP means increases speed, so you travel faster. But it also uses more fuel and has to carry more fuel, so it is heavier. With that increased weight comes increased wing loading, higher stall speeds, and longer runways needed to stop. |
What is engineering? | The application of science to build or make something |
How is engineering design different from the scientific method | It involves researching and planning how to build something. Often there are multiple prototypes as we work to change and test 1 design improvement at a time. |