Take into account that the velocity for both watermelons can be written as follow:
[tex]\begin{gathered} v=gt \\ v^{\prime}=gt^{\prime} \end{gathered}[/tex]Consider that t' = t - 1, that is, second melon is released 1s after realted to the first one. Then:
[tex]v^{\prime}=g(t-1)[/tex]Where g is the acceleration gravitational constant.
If you calculate the difference v - v', you obtain:
[tex]v-v^{\prime}=gt-g(t-1)=gt-gt+g=g[/tex]As you can notice, the difference between the velocities is g, and this is a constant.
Hence, you can conclude that the difference in velocity between melons is constant and has a value of 9.8 m/s^2
