0
$\begingroup$

Consider some very ground pieces of a non sticky solid material and put it on a piece of paper but be careful that these pieces must be very finely ground (somewhat powdery material but should not be exact powder).

Now stuck your used pen or pencil very hard on that material. I observed that some pieces stick around the nib of pen. Now gently push your pen on that material again I found that some material again sticked around the previously stuck material on the nip of pen.

I don't know which force is responsible for sticking of material around the nib of pen someone said that it is adhesion but I don't think adhesion forces play such a strong role here.Am I right or totally wrong?

EDIT

I think that I myself understood which forces are responsible and what is happening in this situation so I am posting the answer below.

$\endgroup$
0

2 Answers 2

0
$\begingroup$

I have not done this in person, but since you say that dipping it a second time into the powder causes more dust to stick to the already stuck dust, I think this is most likely electrostatics at work. If the dust itself is "non-sticky," then something other than adhesion must be happening.

Remember, electrostatic forces are actually quite strong compared to most other fundamental forces. Some kind of adhesion may help this phenomenon out, but for everyday life phenomena electromagnetic forces usually dominate.

$\endgroup$
0
$\begingroup$

If we consider the situation carefully then I think that when we write with a pen then it gets charged(i performed the experiment during completing my notes) due to rubbing the surface of nib of pen and paper(due to friction).

From my study of electrostatics I know that pointed surfaces are very highly charged. Its consequence may be that when we stuck the pen on powder it may result in polarization of powdery particles due to dielectric breakdown and will result in electrostatic attraction between nib of pen and the powdery material.

Please comment if I am wrong somewhere.

$\endgroup$
2
  • 2
    $\begingroup$ What about adhesion due to small amounts of moisture on the pen (or even due to weak contact forces like van der Waals interactions that don't require any exchange of charge)? $\endgroup$ May 3, 2019 at 17:03
  • $\begingroup$ They can also be responsible for that. $\endgroup$ May 4, 2019 at 5:00

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.