A helicopter is ascending vertically with a speed of 8.0 ms^(-1). At a height of 120m above the earth , a package is dropped from a window . How much time does it take for the package to reach the ground ?

A helicopter is ascending vertically with a speed of 8.0 ms^(-1). At a

1.	A helicopter is ascending vertically with a speed of 8.0 ms^(-1). At a height of 120m above the earth , a package is dropped from a window . How much time does it take for the package to reach the ground ?
Answer» Solution :`u=8 m//s, "HEIGHT" H = 120m RARR s=-120m` `s=ut+1/2at^(2) -120=8t-1/2xx9.8xxt^(2)-8t-120=0` `t=(8+-sqrt(64+4xx4.9xx120))/(2xx4.9)=(8+-sqrt(64+2352))/(9.8)=(8+-sqrt(2416))/(9.8)=(8+-49.15)/(9.8)` `t=(8+-49.15)/(9.8)` , (only positive VALUE )`=5.83 sec`