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