Question #6f91b

2 Answers
Gió
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

Gió
Jul 2, 2015

Have a look if it is clearer.

Explanation:

Using the same diagram.
Considering that:
#v_i=7.25 m/s#
#h_1+h_2=25m#
Use: #v_f-v_i=at#
#0=7.25-9.81t_1#
#t_1=0.74s#
Use:
#h_1=v_it_1+1/2at_1^2#
#h_1=7.25*0.74-1/289.81(0.74)^2#
#h_1=2.68m=2.7m#

#h_2=25-2.7=22.3m#
#h=h_2-h_1=19.6m#
to fall down:
#-h_2=-1/2*9.81t_2^2#
#t_2=2.13s#
into #v_f-v_i=at#:
with #v_i=0#
#v_f=21m/s#
and
#T_(comp.te)=t_1+t_2=2.87s#

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