Let’s talk about feet…… FOOT LAB!!!!. Accuracy and Precision. The Goal Measure the distance across the room as precisely as you can using “feet” as your units of measurement. Resources Strip of adding machine tape Your foot. How many feet: Presentation.
Be prepared to present your results to the class when called upon. I will ask you 3 questions.
What was your method for getting the measurement?
How did you maximize the precision?
What is your answer in feet and inches?
Parallax and Precision
Location, location, location! Align eyes directly with indicator to increase accuracy.
Always estimate one place beyond smallest interval.
What is the length of the blue line?
Qualitative measurements - adjectives
Quantitative measurements – involve actual numbers (quantities)
These depend on reliability of the measuring instrument.
These depend on care with which it is read.
The standards of measurement used in science are those of the metricsystem.
The metric system is also known as the International System of Units (SI), established in 1960.
This system’s focus is simplicity and is based on 10 or multiples of 10.
cm, mm, km or m
In Physics these are the most prevalent units of mass used
In Chemistry, you learned about Significant Figures, or Sig Figs. They relate to the precision of the measurement being taken.
In Physics, we won’t focus on Sig Figs as much. We will round answers to nearest tenth or possibly hundredth, so your answers will look like XX.X or XX.XX
Also, round at the end of computation only.
Why do we care?
Effective in gaining, organizing, and applying knowledge
An organized approach in studying problems
Who is considered the “Father” of the Scientific Method?
Founder of Scientific Method
Principle of Inertia
Father of Astronomy, Physics, Modern Science
Controversy: Heliocentrism (opposed Aristotle, Copernicus, and the Church)
When there is more than one operation involved in a mathematical problem, it must be solved by using the correct order of operations .
Remember, calculators will perform operations in the order which you enter them, therefore, you will need to enter the operations in the correct order for the calculator to give you the right answer.
PLEASE EXCUSE MY DEAR AUNT SALLYor justP.E.M.D.A.S.Parentheses
2 x 3 =
(2 x 3) =
6 = 3
2[14 – 32] =
2[14 – 32] =
2[14 – 9] =
Used to convert between different units of measurement
This is done by multiplying by factors of 1
What do you have?
What do you want?
Is your answer going to be larger or smaller than the starting number?
What do you know?
Remember you must be able to cancel out all units except the one you want to end up with
Write down the number and unit that you are starting with
Find out how to arrive at your final unit by using known conversion factors
Set up your conversion factor so that the units cancel
Convert 5 m into km:
Step 1: you start with 5 m
Step 2: you need to get to km
Step 3: you know that: 1km = 1000 m
5 m X 1km =
**Always multiply every number across the top ,then multiply every number across the bottom. Finally divide the product of the top by the product of the bottom. Record number and unit.