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A plastic pen when rubbed with a dry cloth can attract small pieces of paper which 'stick' to it - Junior Cycle Science - Question d - 2009
Question d
A plastic pen when rubbed with a dry cloth can attract small pieces of paper which 'stick' to it. (i) Why does this happen? Why? (ii) Explain why the pieces of p... show full transcript
Worked Solution & Example Answer:A plastic pen when rubbed with a dry cloth can attract small pieces of paper which 'stick' to it - Junior Cycle Science - Question d - 2009
Step 1
(i) Why does this happen?
Answer
When a plastic pen is rubbed with a dry cloth, it becomes electrically charged due to the transfer of electrons between the pen and the cloth. The pen acquires a static charge, which creates an electrostatic force that attracts small pieces of paper. This phenomenon occurs due to the interaction between opposite charges, where the paper, being neutral, induces polarization in response to the charged pen.
Step 2
(ii) Explain why the pieces of paper fall
Answer
The pieces of paper eventually fall from the pen because the pen loses its static charge over time. This loss can occur due to several factors, including grounding, discharge into the air, or contact with other objects that can neutralize the charge. Once the charge diminishes below a certain threshold, the electrostatic force is no longer sufficient to hold the paper pieces against gravity, causing them to fall.