1.1 Measurements

Vocabulary Measurement – a determination of the amount of something Unit – a fixed amount of something like a centimeter of distance English System – measurement system used for everyday measurements in the United States SI – International System of Units used by most countries for everyday measurement and used by the scientific community worldwide

Measurement and Units Measurements Distance, Time, Mass, Volume, Weight, and Temperature Must have a number and a unit

English System

SI

SI Multiply or divide by powers of 10

1.2 Time and Distance

Vocabulary Distance – the amount of space between two points Length – a measured distance Meter – a basic SI unit of length

Time Time is used in two ways What time is it? How much time? The date or time of an event/moment in life How much time? A time interval, for example how long it takes to run a mile

Distance Distance is measured in units of length

Basic Conversions How many minutes are in 1.5 hours? Convert 330 minutes to hours. Men in the 18-34 age group need to be able to run a marathon in 3 hours and 10 minutes to qualify for the Boston Marathon. How many seconds is this?

1.3 Converting Units

Converting SI Units 650 mm = ______ m 142 Km = _____ dm 754,000 cm = ____Km 0.23 m = _____Hm

Vocabulary Conversion Factor – a ratio that has a value of one, and is used when setting up a unit conversion problem Dimensional Analysis – a method of using conversion factors and unit canceling to solve a unit conversion problem

Dimensional Analysis 4.5 ft = ______ cm 175 yd = _______m 2.50 in = ________ mm 50 m = _______ yd

Dimensional Analysis – Part 2 4 gal = _____ fl. oz 3 year = _____ seconds 0.235 g = ________ mg 12 ton = ______ oz

Worksheet Classwork: Complete the evens Homework: Complete the odds

1.4 Significant Digits

Vocabulary Significant Digits – meaningful digits in a measured quantity Accuracy – how close a measurement is to an accepted or true value Precision – describes how close together or reproducible repeated measurements are Resolution – refers to the smallest interval that can be measured

https://youtu.be/Gn97hpEkTiM

Significant Digits It is impossible to make a measurement that is the exact true value of something The first arrow clearly points to 4 cm The second arrow is between 5 and 6 cm. 5.7 cm? 5.8 cm? If you wrote the answer as 5.78543, it would be inaccurate because you cannot tell to that level of precision based on the ruler given

Which digits are significant? Digits that are always significant: Non-zero digits 13 has two significant digits Zeros between two significant digits 104 has three significant digits All final zeros to the right of a decimal point 4.0 has two significant digits Digits that are never significant: Leading zeros to the right of a decimal place 0.002 has one significant digit Final zeros in a number that does not have a decimal point 2000 has one significant digit Note: A decimal point is used after a whole number ending in zero to indicate that the final zero IS significant. 50. cm has two significant digits

Calculations: Significant Digits Your answer can have no more than the measurement with the least amount of significant digits. Example: What is the area of an 8.5 inch by 11.0 inch piece of paper? A = length x width A = 8.5 in x 11.0 in A = 93.5 square inches The smallest amount of significant digits is two, so the answer can only have two: 94 square inches

Classwork P 23 # 1 – 7