Podcast
Questions and Answers
Which of the following is the most accurate description of a base quantity in the context of SI units?
Which of the following is the most accurate description of a base quantity in the context of SI units?
- A fundamental quantity that is not defined in terms of other quantities. (correct)
- A quantity that can be derived from other physical quantities through multiplication and division.
- A quantity that is defined by a combination of other quantities.
- A quantity whose units are based on experimental measurements but are not internationally agreed upon.
If electric charge (Q) is defined by the equation $Q = IT$, where I is electric current and T is time, what type of quantity is electric charge?
If electric charge (Q) is defined by the equation $Q = IT$, where I is electric current and T is time, what type of quantity is electric charge?
- Fundamental Quantity
- Base Quantity
- Supplementary Quantity
- Derived Quantity (correct)
A student measures the length of a table using a ruler. The measurement is 1.5 meters. Which part represents the 'unit' in this physical quantity?
A student measures the length of a table using a ruler. The measurement is 1.5 meters. Which part represents the 'unit' in this physical quantity?
- Length
- Meters (correct)
- 1.5
- 1
Which of the following is NOT a base quantity in the International System of Units (SI)?
Which of the following is NOT a base quantity in the International System of Units (SI)?
A recipe calls for ingredients to be measured in grams. Which base quantity does grams directly relate to?
A recipe calls for ingredients to be measured in grams. Which base quantity does grams directly relate to?
If a scientist is studying the rate of a chemical reaction, which SI base unit would be most relevant for measuring the duration of the reaction?
If a scientist is studying the rate of a chemical reaction, which SI base unit would be most relevant for measuring the duration of the reaction?
When describing the brightness of a computer screen, which SI base unit would be most appropriate?
When describing the brightness of a computer screen, which SI base unit would be most appropriate?
A researcher is investigating the relationship between heat and volume of a gas. Which SI base unit would they use to accurately measure the gas's temperature?
A researcher is investigating the relationship between heat and volume of a gas. Which SI base unit would they use to accurately measure the gas's temperature?
A car travels 20 meters east, then 10 meters north. Which of the following correctly describes the relationship between the distance the car traveled and its displacement?
A car travels 20 meters east, then 10 meters north. Which of the following correctly describes the relationship between the distance the car traveled and its displacement?
Which of the following actions involves only scalar quantities?
Which of the following actions involves only scalar quantities?
A student is measuring the dimensions of a rectangular garden. They measure the length, width, and calculate the area. Which of these measurements are scalar quantities?
A student is measuring the dimensions of a rectangular garden. They measure the length, width, and calculate the area. Which of these measurements are scalar quantities?
An object's weight is measured on Earth and then on the Moon. Which statement accurately describes the difference in measurements, considering weight as a vector quantity?
An object's weight is measured on Earth and then on the Moon. Which statement accurately describes the difference in measurements, considering weight as a vector quantity?
Two forces act on an object: Force A is 5N to the right, and Force B is 3N to the left. What is the net force acting on the object?
Two forces act on an object: Force A is 5N to the right, and Force B is 3N to the left. What is the net force acting on the object?
Flashcards
What are scalar quantities?
What are scalar quantities?
Quantities with magnitude only.
What are vector quantities?
What are vector quantities?
Quantities possessing both magnitude and direction.
How do you add scalars?
How do you add scalars?
Adding scalars uses simple math: 4kg + 6kg = 10kg.
Examples of scalar quantities?
Examples of scalar quantities?
Signup and view all the flashcards
Examples of vector quantities?
Examples of vector quantities?
Signup and view all the flashcards
Physical Quantity
Physical Quantity
Signup and view all the flashcards
Types of Physical Quantities
Types of Physical Quantities
Signup and view all the flashcards
Base Quantity
Base Quantity
Signup and view all the flashcards
Seven Base Quantities
Seven Base Quantities
Signup and view all the flashcards
SI Units for Base Quantities
SI Units for Base Quantities
Signup and view all the flashcards
Derived Quantity
Derived Quantity
Signup and view all the flashcards
SI unit of length
SI unit of length
Signup and view all the flashcards
Scalar quantities
Scalar quantities
Signup and view all the flashcards
Study Notes
- Chapter 1 focuses on physical quantities, units, and measurement
SI Units
- SI units is short for the International System of Units
- Base Quantities are those from which all other quantities are derived
- There are seven internationally agreed upon base quantities
Base Quantities
- Length has a metre as its name of unit; its symbol of unit is m
- Mass has a kilogram as its name of unit; its symbol of unit is kg
- Time has a second as its name of unit; its symbol of unit is s
- Electric current has an ampere as its name of unit; its symbol of unit is A
- Temperature has a kelvin as its name of unit; its symbol of unit is K
- Amount of substance has a mole as its name of unit; its symbol of unit is mol
- Luminous intensity has a candela as its name of unit; its symbol of unit is cd
- The standard kilogram is made from a platinum iridium cylinder
Derived Quantities
- Derived quantities are determined by combining base quantities.
Examples of derived quantities
- Area = length x width and uses the unit square metre, symbol m²
- Volume = length x width x height and uses the unit cubic metre, symbol m³
- Frequency = 1/period and uses the unit hertz, symbol Hz
- Density = mass/volume and uses the unit kilogram per cubic metre, and the symbol kg m⁻³
- Velocity/speed = displacement/time and uses the unit metre per second, symbol m s⁻¹
- Acceleration= velocity change/time and uses the unit meters per second squared with symbol m s⁻²
- Force = mass x acceleration and uses the unit Newton, symbol N or m kg s⁻²
- Pressure = force/area and uses the unit Pascal, symbol Pa or Nm⁻²
- Energy = force x displacement and uses the unit Joule, symbol J or Nm
- Power = work/time and uses the unit Watt, symbol W or J s⁻¹
- Quantity of electricity = current x time and uses the unit Coulomb, symbol C or As
- Potential difference = energy/charge and uses the unit Volts, symbol V or WA⁻¹
- Electric resistance= potential difference/current and uses the unit Ohm, symbol Ω or VA⁻¹
Key concepts
- A physical quantity is measurable and has a numerical magnitude and a unit
- Physical quantities are classified into base quantities and quantities that are derived
- Length, mass, time, current, temperature, amount of substance, and luminous intensity are all base quantities
- Metre, kilogram and second are the SI units for length, mass and time respectively
Scalars and Vectors
- Scalar quantities only have magnitude
- Scalar quantities are added/ subtracted using basic arithmetic, for example: 4kg + 6kg = 10kg
- Vector quantities have magnitude AND direction, for example: A force with magnitude = 100N and direction = left
Examples of scalars and vectors in physics
- Distance is a scalar, displacement is a vector
- Speed is a scalar, velocity is a vector
- Mass is a scalar, weight is a vector
- Time is a scalar, acceleration is a vector
- Pressure is a scalar, force is a vector
- Energy is a scalar, momentum is a vector
- Volume is a scalar
- Density is a scalar
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
