2 The International System SI Units2The International SystemTo avoid confusion, scientists established the International System of Units, or SI, in 1960 as the accepted system for measurement.
3 The International System SI Units2The International SystemThe SI units are related by multiples of ten.Any SI unit can be converted to a smaller or larger SI unit by multiplying by a power of 10.The new unit is renamed by changing the prefix.
4 The International System SI Units2The International System
5 Length 2 Length is defined as the distance between two points. SI Units2LengthLength is defined as the distance between two points.The meter (m) is the SI unit of length. One meter is about the length of a baseball bat.
6 SI Units2LengthSmaller objects can be measured in centimeters (cm) or millimeters (mm). Thelength of your textbook or pencil would be measured in centimeters.
7 A Long Way 2 To measure long distances, you use kilometers. SI Units2A Long WayTo measure long distances, you use kilometers.Kilometers might be most familiar to you as the distance traveled in a car or the measure of a long-distance race.The course of a marathon is measured carefully so that the competitors run 42.2 km.When you drive from New York to Los Angeles, you cover 4,501 km.
8 SI Units2VolumeThe amount of space an object occupies is its volume. The cubic meter (m3) is the SI unit of volume.
9 SI Units2VolumeTo find the volume of a square or rectangular object, such as a brick or your textbook, measure its length, width, and height and multiply them together.
10 Volume by Immersion 2 Not all objects have an even, regular shape. SI Units2Volume by ImmersionNot all objects have an even, regular shape.When you measure the volume of an irregular object, you start with a known volume of water and drop in, or immerse, the object.The increase in the volume of water is equal to the volume of the object.
11 SI Units2MassThe mass of an object measures the amount of matter in the object.The kilogram (kg) is the SI unit for mass.You can determine mass with a triple-beam balance.The balance compares an object to a known mass. Weight and mass are not the same. Mass depends only on the amount of matter in an object.
12 Weight 2 Weight is a measurement of force. SI Units2WeightWeight is a measurement of force.The SI unit for weight is the Newton (N).Weight depends on gravity, which can change depending on where the object is located.
13 SI Units2WeightIf you were to travel to other planets, your weight would change, even though you would still be the same size and have the same mass.This is because gravitational force is different on each planet.
14 SI Units2TemperatureThe physical property of temperature is related to how hot or cold an object is.Temperature is a measure of the kinetic energy, or energy of motion, of the particles that make up matter.Temperature is measured in SI with the Kelvin (K) scale.
15 SI Units2TemperatureThe Fahrenheit and Celsius temperature scales are the two most common scales used on thermometers and in classroom laboratories.The Kelvin scale starts at 0 K. In theory, 0 K is the coldest temperature possible in nature.
16 Time and Rates 2 Time is the interval between two events. SI Units2Time and RatesTime is the interval between two events.The SI unit of time is the second (s).Time also is measured in hours (h).A rate is the amount of change of one measurement in a given amount of time.One rate you are familiar with is speed, which is the distance traveled in a given time.
17 Section Check2Question 1If everyone used a different standard of measurement, there would be no way to know how one scientist’s data compared with another scientist’s data. Instead, scientists all use an agreed-upon standard of measurement known as _______.
18 A. English standard of measurement B. European standard of measurement Section Check2A. English standard of measurementB. European standard of measurementC. International system of unitsD. North American system of units
19 Section Check2AnswerThe correct answer is C. “SI” is the International System of Units.
20 Section Check2Question 2If you were measuring a particular mass, for example, a big lump of cookie dough, you would measure it in terms of _______.A. kilogramsB. litersC. newtonsD. watts
21 Section Check2AnswerThe answer is A. A kilogram is a unit of mass.
22 Section Check2Question 3A spring scale can show you how much a baseball mitt weighs, but why might this figure change if you were to weigh the same object on Mars?
23 Section Check2AnswerGravitational pull is different on different planets. The mass of the mitt stays the same no matter where it is, but its weight can change.