Answer:2t
Explanation:
Given
Jason throwing watermelon at speed v and it spend t time in air
time to reach max height
[tex]v_f=u_i+at'[/tex]
0=v-gt'
[tex]t'=\frac{v}{g}[/tex]
and time to reach bottom is also t'
t=2t'
[tex]t=2\frac{v}{g}[/tex]
For guy throws his watermelon at speed 2v
So total time in air will be
[tex]t''=2\frac{2v}{g}[/tex]
[tex]t''=4\frac{v}{g}[/tex]
t''=2t