physical quantities and units q

As level

what are physical quantities?

anything that can be meaasured

what two things do physical quantities need to have?

a unit and magnitude

what are physical quantities divided into

base and derived

what are base quantities

basic quantities which are used to obtain derived quantities but they cant be obtained from other qunatities

what is the base unit of length

m

what is the base unit of mass

kg

what is the base unit of time

s

what is the base unit of temperature

K

wht is the base unit of electric current

A

what is the base unit of the amount of substance

mol

what is the base unit of area

m²

what is the base unit of volume

m³

what is the base unit of density

kg m^-3

what is the formula of density

mass/volume

what is the base unit of speed

ms^-1

what is the base unit of acceleration

m s^-2

what is the si base unit of force

kg ms^-2

what is the si base unit of moment

kgm²s^-2

what is the formula of moment

force x distance

what is the si base unit of work done

kg m² s^-2

what is the base unit of energy

kg m² s^-2

what is the base unit of momentum

kg ms^-1

what is the formula of momentum

mass x velocity

what is the base si unit for pressure

kg m^-1 s^-2

what is the base si unit for power

kg m² s^-3

what is the formula of power

work done / time

what is the si base unit of amount of charge

As

what is the si base unit of p.d, e.m.f, voltage

kg m² s^-3 A^-1

what is the si base unit of resistance

kg m² s^-3 A^-2

what is the formula of voltage

work /charge

what is the base unit of resistivity

kg m³ s^-3 A^-2

what is the formula to find resistivity

resistance x area / length

what is homogenity

it is used to check the validity of an equation

what is the value of pico

10^-12

what is the value of nano

10^-9

what is the value of micro

10^-6

what is the value of mili

10^-3

what is the value of centi

10^-2

what is the value of deci

10^-1

what is the value of kilo

10³

what is the value of mega

10⁶

what is the value of giga

10⁹

what is the value of tera

10¹²

what do we do when we need to remove a prefix

multiply it

what do we do when we need to add a prefix

divide it

what are errors

theyre uncertainties which may be there in an experiment

what causes errors?

• lack of observational skills of person doing experiment

• limitation of apparatus / wrong procedure followed

• variations in enviroment conditions

what are errors divided into

systematic and random

what are systematic errors

causes observations to be either overstated or understated

how can the systematic error be judged

by taking the difference between the average and actual