what is radian and steradian
Answers
Step-by-step explanation:
this is radian
according to my knowledge
Answer:
a dimensionless quantity means that the quantity is not associated with any dimension of length, time, mass etc .. which roughly means that the quantity is sort of a number .. it is a crude number eveytime and it doesn't need anything else .. for ex .. while looking at a quantity with dimensions, such as 2 m .. we see, there are two parts 2 and metre .. you just can't say something is 2m unless you know the exact length of a metre ..
but, if i say i have 2 hands .. i exactly know how much 2 is ..
A dimensionless quantity can generally be seen as some sort of ratio of two quantities with same dimensions .. which leads to cancelling of dimensions whichever value you take ..
such is the case with these two .. an angle is the ratio of two lengths !!! you may dont know it yet, but this is true .. open page 51 of ncert mathematics class 11 .. you can see that clearly .. LENGTH OF ARC / LENGTH OF RADIUS = ANGLE .. bt, remember that this angle is not in degrees, but in radian that you will read about later .. whatever be the length of the arc and the radius .. when you divide the two .. it must be a number with no dimensions i.e. no m, cm, km, sec, hour, year, g, kg, etc associated with it .. same goes with the solid angle .. it is a ratio of squares of lengths, and i dont think you need to dig that deeper