[填空题]
A stone is dropped from ts-:mrkpyn*p0;vnz bt8 8c)-l.b f aebhe roof of a high building. A second stone is uyx njy,a p1.ko05b9g dropped 1.80 s later. How far apart are the stones when the s9 5,0a y.jp1xyuo bkngecond one has reached a speed of $24 \; m/s$? $m$
