Question #6f91b

2 Answers
Jul 1, 2015

I found the following values (in red in the explanation):
(but check carefully my math!!!)

Explanation:

Have a look:
enter image source here

Jul 2, 2015

Have a look if it is clearer.

Explanation:

Using the same diagram.
Considering that:
vi=7.25ms
h1+h2=25m
Use: vfvi=at
0=7.259.81t1
t1=0.74s
Use:
h1=vit1+12at21
h1=7.250.741289.81(0.74)2
h1=2.68m=2.7m

h2=252.7=22.3m
h=h2h1=19.6m
to fall down:
h2=129.81t22
t2=2.13s
into vfvi=at:
with vi=0
vf=21ms
and
Tcomp.te=t1+t2=2.87s