[填空题]
Two children are playing on two trampolines. The first chi t-9xol7dtr 7cld can bounce up one7kc.+zlsob ; *wq4z ,+nmoobu-and-a-half times hi 47bwm++ool ;*zb.,nocqu kzsgher than the second child. The initial speed up of the second child is $5.0 m/s $.
(a) Find the maximum height the second child reaches. $\approx$ m(retain one decimal places)
(b) What is the initial speed of the first child? $\approx$ m/s(retain one decimal places)
(c) How long was the first child in the air? s
