Here, `u=49m//s , h=?`

total time of ascent + time of descent `=t+t=2t=?`

At maximum height, finaly velocity,`v=0`

acceleration `=-g=-9.8m//s^(2)`

from `v^(2)-u^(2)gh, 0-(49)^(2)=2(-9.8)h or h=(49xx49)/(2xx9.8)=122.5m`

from `v=u+g t, 0=49-9.8t or t=49/9.8=5s`

Total time`=2t,=10s`.