- #1
physics user1
Our professor introduced us to dimensional analysis and told us that we can use it to predict how some variables are proportional to others, for example:
I have a ball at a certain height and i want to know the time it requires to touch the grond, i can make a guess that it will depend on the height with dimension [L] on g.[L]/[T]^2and on the mass m [M]...
Making calculations: T~ [M]^a [L]^b [L]^c [T]^-2c and i find a=0 b= 1/2 and c= -1/2 that leads to t~h^1/2 * g^(-1/2)
But what if i said in the assumption that the time depends also on the friction force? Or the initial velocity?
Why can't i use dimensional analysis to find a relation between time and these others quantities?
I have a ball at a certain height and i want to know the time it requires to touch the grond, i can make a guess that it will depend on the height with dimension [L] on g.[L]/[T]^2and on the mass m [M]...
Making calculations: T~ [M]^a [L]^b [L]^c [T]^-2c and i find a=0 b= 1/2 and c= -1/2 that leads to t~h^1/2 * g^(-1/2)
But what if i said in the assumption that the time depends also on the friction force? Or the initial velocity?
Why can't i use dimensional analysis to find a relation between time and these others quantities?