Post on 13-Dec-2015
Introduction to Physics2015-2016
What is Physics?
• Take out a sheet of scrap paper.• Write down some things that you think
might fit into the realm of physics.
What is Physics?
• The study of interactions of matter and energy
Understanding the Natural World• Why are things the way they are?
• Can we use explanations to predict what we observe?
• How do we know what we believe to be true?
• How has mankind progressed so far so quickly?
The Technology Boom
• How has mankind progressed so quickly?
The Scientific Method
• Observation• Hypothesis• Prediction• Experiment• Conclusion
The Scientific Method
• Observation• The research stage• Directly affects the quality of your experiment• Ask, “What has already been done to investigate _____?”
• Hypothesis• Prediction• Experiment• Conclusion
The Scientific Method
• Observation• Hypothesis• a falsifiable statement about the nature of things• Ask, “What do we want to prove/disprove?”
• Prediction• Experiment• Conclusion
The Scientific Method
• Observation• Hypothesis• Prediction• An educated guess about the outcome of a test/experiment• Declare, “Under these specific conditions, I think _____ will occur.”
• Experiment• Conclusion
The Scientific Method
• Observation• Hypothesis• Prediction• Experiment• Designed specifically to test your hypothesis• Controlled setting, keen observation, & diligent recording of data• Ask, “What can we measure?”
• Conclusion
The Scientific Method
• Observation• Hypothesis• Prediction• Experiment• Conclusion• Analysis of data leading toward either a plausible confirmation or rejection of
the hypothesis.• Ask, “Did the outcome agree with our hypothesis?”
Eratosthenes
• 276 – 194 BC• Greek mathematician, geographer, &
astronomer
• Accurately calculated the circumference of the earth
Observation (or research)
• Circumference of a circle?
• Arc length?
• Is there any other useful information that we could obtain before moving on?
Hypothesis
• Common people at the time might have said:
“The earth is not round. It is flat.”
“We do not have the means to measure the circumference of a round earth.”
• What might be a good hypothesis?
Prediction
• The logic:
Circumference = 2π (Radius of Earth) Distance at Surface = (Radius of Earth)(Angle of Deviation)
• What might be a good prediction?
Experiment
• What can we measure?
• How can we measure it?
Conclusion
What have we learned?
s = rθArc Length = (Radius)(Angle)Distance on Earth’s Surface = (Radius of Earth)(Angle)5000 Stadia = (Radius of Earth)(2 π /50 radians)(5000 Stadia)(50/2π) = Radius of Earth(5000 Stadia)(0.0976 miles/stadia)(50/2 π) = Radius of EarthRadius of Earth = 3883 miles
Actual: 3959 miles
C = 2πrCircumference of Earth = 2π(Radius of Earth)Circumference of Earth = 2π(3883 miles)Circumference of Earth =24398 miles
Actual: 24,901 miles
Types of Physicists
• Experimental
• Theoretical
Dr. Peter Higgs