Presentation Transcript

1. Thinking Like a Scientist:The Scientific Method

2. Steps in the Scientific Method Observation Hypothesis – an “educated guess” Experiment Theory – a well tested hypothesis Scientific Law – a theory that is widely accepted as true (Example: Theory of Gravity)
3. Definitions Hypothesis– an educated guess that explains your observations Experiment– is a means of testing your hypothesis Theory – is a synthesis of a large body of information that supports your hypothesis Scientific Law– a concise statement that summarizes the results of many observations and experiments
4. Scientific Hypotheses Must Be Testable “No number of experiments can prove me right; a single experiment can prove me wrong” - Albert Einstein
5. Is a scientific fact something that is absolute and unchanging? No The goal of science is the search for truth about natural phenomena However no phenomenon can be proven to be true, only supported by evidence
6. Are These Hypotheses Scientific? “The alignment of the planets in the sky determine the best time for making decisions” “Atoms are the smallest particles of matter.” “The universe is surrounded by a second universe, the existence of which cannot be detected by scientsts” “Albert Einstein was the greatest physicist of the twentieth century.” String Theory
7. A scientist must be prepared to abandon an idea Aristotle claimed that an object twice as heavy as another falls twice as fast. Even though this idea was wrong, it was held to be true for nearly 2000 years because of his compelling authority as a philosopher
8. Historical Examples of Good Observations Vaccine for smallpox – Edward Jenner notices that people infected with less virulent cowpox become immune to the more virulent smallpox Genetic Inheritance – Gregor Mendel observed that genetic traits could be transferred by cross-pollenating pea plants
9. Don’t be afraid of Failure Thomas Eddison tried many different types of materials to use as a filament for the light bulb. Many failed. “I have not failed. I've just found 10000 ways that won't work.” - Thomas Eddison
10. Mechanics of Linear Motion Rate – distance divided by time Relative motion– motion of one object in respect to a second object Speed – is a measure of how fast something is moving Instantaneous Speed – the speed at any one instant in time
11. Linear Motion Continued… Average Speed average speed = total distance covered time interval
12. Linear Motion Continued… Velocity – is speed in a given direction In everyday language, speed and velocity are often used interchangeably, but in physics velocities is how fast and in what direction something travels
13. Linear Motion Continued… Acceleration – the rate at which velocity is changing acceleration = change in velocity time interval
14. Linear Motion Continued… instantaneous speed = acceleration x elapsed time V = g t