Answer:2t
Explanation:
Given
Jason throwing watermelon at speed v and it spend t time in air
time to reach max height

0=v-gt'

and time to reach bottom is also t'
t=2t'

For guy throws his watermelon at speed 2v
So total time in air will be


t''=2t
Is there any numbers to your question?
Keep in mind, the energy is conserved in a pendulum.
Here’s more information:
https://blogs.bu.edu/ggarber/interlace/pendulum/energy-in-a-pendulum/
Answer:
C- An explanation for why matter cannot be created or destroyed
Explanation:
The kinetic energy of the small ball before the collision is
KE = (1/2) (mass) (speed)²
= (1/2) (2 kg) (1.5 m/s)
= (1 kg) (2.25 m²/s²)
= 2.25 joules.
Now is a good time to review the Law of Conservation of Energy:
Energy is never created or destroyed.
If it seems that some energy disappeared,
it actually had to go somewhere.
And if it seems like some energy magically appeared,
it actually had to come from somewhere.
The small ball has 2.25 joules of kinetic energy before the collision.
If the small ball doesn't have a jet engine on it or a hamster inside,
and does not stop briefly to eat spinach, then there won't be any
more kinetic energy than that after the collision. The large ball
and the small ball will just have to share the same 2.25 joules.