Questions and Answers
What is the formula to calculate the average pulse rate?
Sum of the pulse rates of all students divided by the number of students.
The SI unit for length is __________.
metre
The SI unit for mass is __________.
kilogram
Which of the following is NOT an SI unit of time?
Signup and view all the answers
Millimeters, centimeters, and kilometers are units of mass.
Signup and view all the answers
What is a leap year?
Signup and view all the answers
Parallax error is caused when readings of scales are taken from an __________.
Signup and view all the answers
Match the following measurements with their correct SI units:
Signup and view all the answers
What is a fundamental physical quantity?
Signup and view all the answers
What does measurement refer to?
Signup and view all the answers
What is measurement?
Signup and view all the answers
Which of the following is a physical quantity that can be measured?
Signup and view all the answers
Measurements using body parts are standard.
Signup and view all the answers
What is the standard unit of length?
Signup and view all the answers
The SI unit of mass is _____
Signup and view all the answers
Which of the following is NOT a fundamental physical quantity?
Signup and view all the answers
What are the two components of a measurement value?
Signup and view all the answers
What is the purpose of a thermometer?
Signup and view all the answers
Match the following temperature scales with their freezing and boiling points of water:
Signup and view all the answers
What is the SI unit for measuring time?
Signup and view all the answers
A 12-hour clock shows the same time twice a day.
Signup and view all the answers
A leap year has _____ days.
Signup and view all the answers
What are the two primary formats for reading time on clocks?
Signup and view all the answers
Study Notes
Measurement of Quantities
- Measurement is the act of determining the size, mass, degree of hotness or coldness of an object or time of an activity using specific devices.
- A quantity that can be measured is called a physical quantity.
- Measurement values have two parts: numerical value and unit.
Need for Standard Units of Measurement
- Ancient methods of measuring length and time were not accurate and reliable, and varied across the world.
- Standard units of measurement were developed to overcome these limitations.
- The International System of Units (SI) is widely accepted and used around the world.
SI Units
- There are seven fundamental physical quantities with standard units: length (meter, m), mass (kilogram, kg), time (second, s), electric current (ampere, A), temperature (kelvin, K), amount of substance (mole, mol), and luminous intensity (candela, cd).
- Derived quantities are obtained by combining two or more fundamental physical quantities.
- Units of physical quantities were named in different ways, such as from Latin, Greek, or French words, and some are named after scientists.
Rules to Represent Values in SI Units
- Units are written in lower case letters, except for those named after scientists, which have the first letter in upper case.
- Symbols and unit names should not be pluralized.
- Multiples and submultiples of units have specific prefixes and symbols.
Measurement of Time
- Time can be measured in different units, including seconds, minutes, hours, days, weeks, months, and years.
- The SI unit of time is the second (s).
- Relationships between various short time-measuring units are:
- 60 seconds = 1 minute
- 60 minutes = 1 hour
- 24 hours = 1 day
- Relationships between various long time-measuring units are:
- 7 days = 1 week
- 30 or 31 days = 1 month
- 12 months = 1 year
- 10 years = 1 decade
- 100 years = 1 century
- 1000 years = 1 millennium
- Clocks are used to measure time within a day and can display time in 12-hour or 24-hour format.
Calendars
- Calendars measure time in days, weeks, and months.
- There are 12 months in a year, and each month has a fixed number of days.
- A trick to remember the number of days in each month is to use the knuckles and grooves of the left hand.
- Leap years have 29 days in February.
- The years with 366 days are called leap years, and the years with 365 days are called normal years.
- Earth revolves around the sun in 365 and a quarter days.### Temperature Measurement
- Temperature is the degree of hotness or coldness of an object.
- Units of temperature measurement: degree Celsius (°C), degree Fahrenheit (°F), and kelvin (K).
- The instrument used to measure temperature is called a thermometer.
- A thermometer consists of three parts: the bulb, stem, and scale.
Temperature Scales
- Celsius scale: developed by Anders Celsius, unit is degree Celsius (°C), freezing point of water is 0 °C, and boiling point is 100 °C.
- Fahrenheit scale: developed by Daniel Gabriel Fahrenheit, unit is degree Fahrenheit (°F), freezing point of water is 32 °F, and boiling point is 212 °F.
- Kelvin scale: developed by Lord Kelvin, unit is kelvin (K), freezing point of water is 273 K, and boiling point is 373 K.
Types of Thermometers
- Clinical thermometer: used to measure the temperature of the human body, normal temperature is around 37 °C or 98.6 °F.
- Laboratory thermometer: used in laboratories during experiments, range of temperature measurement is between -10 °C and 110 °C.
- Digital thermometer: electronic thermometer that does not contain mercury, temperature is easier to read.
- Maximum-minimum thermometer: measures the maximum and minimum temperatures during a day, range is -30 °C to 50 °C.
Measurement of Physical Quantities
- Physical quantity: a quantity that can be measured, e.g., length, area, mass, time, and temperature.
- Fundamental physical quantity: a physical quantity that does not depend on other quantities, e.g., length, mass, and time.
- Derived physical quantity: a physical quantity whose units can be obtained by combining units of two or more fundamental physical quantities.
Measurement of Length
- Units of measurement: metre (m), millimetre (mm), centimetre (cm), and kilometre (km).
- Instruments used to measure length: rulers, measuring tapes, Vernier callipers, and screw gauges.
Measurement of Area
- Units of measurement: square metre (m²), square millimetre (mm²), square centimetre (cm²), and square kilometre (km²).
- Instruments used to measure area: graph sheets and square metre scales.
Measurement of Mass
- Units of measurement: kilogram (kg), gram (g), and milligram (mg).
- Instruments used to measure mass: beam balance and digital balance.
Measurement of Time
- Units of measurement: second (s), millisecond (ms), minute (min), and hour (hr).
- Instruments used to measure time: sundials, quartz clocks, water clocks, and sand clocks.
Miscellaneous
- Parallax error: the error produced when readings of scales are taken from an angle.
- Leap year: a year that has 366 days.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers the basics of measurement in daily life, including measurement of length, area, mass, time, and temperature in SI units. It also explains the need for measurement and the difference between accurate and approximate measurements.
