What i got was
speed of impact that is 44.27 m/s
or 159.38 km/h
time until impact is 4.525
and last is the Energy at impact which I calauated outcome was 73500.00 joules
Larry Finkelstein, Norman Fischer, and Cassius Schwartz have been overlooked, in my opinion.
The first law of thermodynamics states that:

where

is the variation of internal energy of the system
Q is the heat absorbed by the system
L is the work done by the system on the surrounding.
In this problem, the system absorbs 15 J of heat, so Q=+15 J (with positive sign, since it is heat absorbed by the system) while the work done by the system is L=+7 J (with positive sign, since it is work done by the system), so the variation of internal energy is
Answer:
(C) T
The tension T at equilibrium will be equal to the Buoyant force.
The Buoyant force is given by:
Fb = density x acceleration due to gravity x volume displaced
The change in height doesn't affect the Buoyant force and hence the tension.
Note: The figure of question is added in the attachment
The answer would be 21.6 but rounded up it would be 22J.