72 cm/sec72 \mathrm{~cm} / \mathrm{sec}72 cm/sec
80 cm/sec80 \mathrm{~cm} / \mathrm{sec}80 cm/sec
90 cm/sec90 \mathrm{~cm} / \mathrm{sec}90 cm/sec
120 cm/sec120 \mathrm{~cm} / \mathrm{sec}120 cm/sec