[填空题]
Two children are playing on t* e 47pb1ssv ;pb;heza:y h7cewo trampnb xn3de76o7ns:+vmjdb- q9 molines. The first child can bounce up one-and-a-half tiqn j 9dnexo3 77svb6+:bnmdm-mes higher 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
