Air friction on a A4 paper ( Classical Mechanics )

bob195
Messages
3
Reaction score
0

Homework Statement



How could u find the drag/friction due to air on a A4 size page dropped perpendicular to the ground. There are about 20 sheets and is dropped about waist height. The tricky thing is no instruments are aloud. Only your senses...

Homework Equations



F=-cv where c is the constant due to air friction. v is the vel and F the force of air

The Attempt at a Solution



have no clue because i would think u would at least need a stop watch.
 
Physics news on Phys.org
If you are given no instruments you will need to make estimates.
 
what estimates? u will have c for the friction and g for the gravity.u could considers some sort of acceleration from looking at the system.could it be done? i would think it would be of the function speed and maybe have to differentiate a few times but would not know where to start...
 
Because of the lack of instrument the best that can be done is a crude estimate.The falling paper tends to rock to and fro but there doesn't seem to be a net vertical acceleration.I think you are expected to assume it reaches terminal velocity this being when the weight of the paper is balanced by air resistance.
 
thanks Dadface!
 
Thread 'Need help understanding this figure on energy levels'
This figure is from "Introduction to Quantum Mechanics" by Griffiths (3rd edition). It is available to download. It is from page 142. I am hoping the usual people on this site will give me a hand understanding what is going on in the figure. After the equation (4.50) it says "It is customary to introduce the principal quantum number, ##n##, which simply orders the allowed energies, starting with 1 for the ground state. (see the figure)" I still don't understand the figure :( Here is...
Thread 'Understanding how to "tack on" the time wiggle factor'
The last problem I posted on QM made it into advanced homework help, that is why I am putting it here. I am sorry for any hassle imposed on the moderators by myself. Part (a) is quite easy. We get $$\sigma_1 = 2\lambda, \mathbf{v}_1 = \begin{pmatrix} 0 \\ 0 \\ 1 \end{pmatrix} \sigma_2 = \lambda, \mathbf{v}_2 = \begin{pmatrix} 1/\sqrt{2} \\ 1/\sqrt{2} \\ 0 \end{pmatrix} \sigma_3 = -\lambda, \mathbf{v}_3 = \begin{pmatrix} 1/\sqrt{2} \\ -1/\sqrt{2} \\ 0 \end{pmatrix} $$ There are two ways...
Back
Top