Question #7ef68

2 Answers
May 18, 2016

Answer:

#h=25*5=125 " "meters"#

Explanation:

#" let x be displacement in the first second"#
#"for t=2" rarr 3x#
#"for t=3" rarr 5x#

#"total="x+3x+5x=9x#

#"thus:"#

#x,3x,5x,7x,9x#

#"total distance="x+3x+5x+7x+9x=25x#

#x=1/2*g*t^2=1/2*10*1=5" displacement for the first second "#

#h=25*5=125 " "meters"#

May 18, 2016

Answer:

#h = 125, s_3 = 45, t_f = 5#

Explanation:

The space covered during the fall is given by
#s = h-1/2g* t^2#
after #3#[s] we have
#eq_1->h-s_3 = h-1/2 g* 3^2#
Being #t_f# the impact time we have
#eq_2->0=h-1/2g*t_f^2#
and at #t_f-1# we have
#eq_3->s_3=h-1/2g*(t_f-1)^2#
Solving #{eq_1,eq_2,eq_3}# for #h,s_3,t_f# we obtain
#h = 125, s_3 = 45, t_f = 5#