With your group members, put all of your graphs from the lab on whiteboards.

1. Title page2. Make these headings stand out (bold, italics, larger font, etc)3. Units go in the column heading only for a data table.4. Independent and dependent variables?5. Historical context/motivation for doing the lab?6. Type all lab reports7. How did you decide on the number of trials to do?8. How did you decide on the range of your independent

variable?9. No need to list all materials. 10. Don’t use second person. 11. Apparatus means equipment or materials. 12. Period: time it takes to complete one cycle

Whiteboard Requirements

• Names• Big enough to read• Meaningful color

Pendulum Lab Conclusions

• Mass• Amplitude• Length

Accuracy / Percent Error

• We often want to compare an “accepted” value to our measurement to see how close we are.

• We calculate the accuracy / percent error so that we can easily compare different measurements.

Accuracy Calculation ExamplesEx. 1: The experts tell us that the equation

that relates mass and force for a lab is .

a). If a lab group measures a mass of 2.7 kg, what force should they measure?

b). In the lab, they recorded a force of 10.9 N with a mass of 2.7 kg. What is their percent error?% 𝐸𝑟𝑟𝑜𝑟=

10.9𝑁−11.45𝑁11.45𝑁

×100%=−4.8% 𝑒𝑟𝑟𝑜𝑟

Ex. 2: Theoretically, in a certain electrical circuit, the relationship between current and resistance can be described by the equation , where I represents the current. What is the accuracy of a measurement of 0.45 A of current when the resistance is 400 Ω

% 𝐸𝑟𝑟𝑜𝑟=0.45 𝐴−0.3425 𝐴

0.3425 𝐴×100%=31.4% 𝑒𝑟𝑟𝑜𝑟

𝐼 h𝑡 𝑒𝑜𝑟𝑒𝑡𝑖𝑐𝑎𝑙=137400

=0.3425 𝐴(𝑎𝑐𝑐𝑒𝑝𝑡𝑒𝑑 𝑣𝑎𝑙𝑢𝑒)

So what do experts say about a pendulum…?

• After many trials in different laboratories around the world, with much better equipment than we have, the equation for the period of a pendulum when swung with small amplitudes is

𝑇=2√𝑙

What is the shape of a graph of a square root function?

• So how does the period you measured compared to what it should theoretically be?

• How can you explain the differences?• You need to show this calculation and

discuss your error in your lab report.

Types of Reasoning/Logic

• Inductive Reasoning– Starting from data and then recognizing general

patterns, making generalizations, and drawing conclusions.

– Examples:• Development of theory of evolution• Statistical sociology• Our physics labs

Types of Reasoning/Logic

• Deductive Reasoning– Starting from principles, patterns, propositions

or equations, then using these to draw conclusions or make predictions.

– Examples:• Discovery of a fossil fish with legs• Mathematics• Applying physics

• Now you are going to analyze some data qualitatively. You will be working with the person sitting diagonally across from you at your table.