Tolong bantu jawab soal nomor ini please 🙏

<p>Jawabannya adalah b. 10 m/s</p><p>Tampaknya sih pakai hukum kekekalan energi mekanik</p><p>&nbsp;</p><p>Tahap-tahap pengerjaan:</p><p>1. Em = Ek (karena benda diam, Ek = 0) + m . g . h&nbsp;</p><p>&nbsp; &nbsp; &nbsp;Em1 = 0 + 2000 . 10 . 20 = 400.000 Joule &lt;--- Jumlah energi mekanik &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;untuk seterusnya</p><p>&nbsp;</p><p>2. 400.000 &nbsp;= Ek + 2000 . 10 . 15 &lt;---- &nbsp;Ketinggian saat di C</p><p>&nbsp; &nbsp; &nbsp;400.000 = Ek + 300.000</p><p>&nbsp; &nbsp; &nbsp;Ek = 400.000 - 300.000 = 100.000</p><p>&nbsp; &nbsp; &nbsp;Ek = ½ 2000 . v²</p><p>&nbsp; &nbsp; &nbsp;100.000 = 1000 . v²</p><p>^{&nbsp; &nbsp; &nbsp;&nbsp;}100 = v²</p><p>^{&nbsp; &nbsp; &nbsp;&nbsp;}v = √100 = 10 m/s</p><p>&nbsp;</p><p>Semoga membantu, maaf jika salah ☺&nbsp;</p>