<p>@Qwerty</p>
<p>Can’t remember details of the string tension one.</p>
<p>For the magnet being attracted by both ends of the metal bar, it was definitely that the metal bar could be magnetized.</p>
<p>@Qwerty</p>
<p>Can’t remember details of the string tension one.</p>
<p>For the magnet being attracted by both ends of the metal bar, it was definitely that the metal bar could be magnetized.</p>