Topic 1- Physical Quantities And Units. Flashcards
Learn the SI system, quantities and recall units.
What is a physical quantity?
It is a feature of something that can be measured. They have a numerical value and a unit.
What are the SI base quantities and their units?
Mass(kg), length(m), time(s), current(A), temperature(K), amount of substance(mol)
What is a derived unit?
They are a combination of the base units that are multiplied or divided, but never added or subtracted.
What is a homogeneous equation?
When each term in the equation have the same base units
What is a scalar quantity?
A quantity that can be described fully by giving its magnitude.
What is a vector quantity?
A quantity that can be described by its magnitude and direction.
What is a vector quantity?
A quantity that can be described by its magnitude and direction.
Give 3 examples of scalar quantities
Mass, speed, pressure, temperature
Give three examples of vector quantities
Weight, velocity, acceleration, force
How do you know when to add, or subtract vectors?
If the two vectors are moving in the same direction (0°) then we add, and if the two vectors are moving in opposite directions(180°) then we subtract.
What is the combined effect of two vectors called?
The resultant
